First, you can tell people are very young by looking at their join dates. A lot of people (if not all) that have Pac-Man in their avatar joined 2009 and earlier.
Now, the fact is people don't like Pac-Man anymore. Look at the sales of his last game.
Wii U sales
3DS sales
In total between the two systems, the game sold 43,711 units. This equals total revenue of 2.1 million. That seems like a lot, but consider the fact that the normal game budget can be anywhere from 15 to 50 million, then you can see how bad this was. Pac-Man and the Ghostly Adventures likely did not break even. The game is also sold on the PS3 and 360, but those sales aren't much better. Total sales for both are 36,365. Out of 4 systems, the game can't even break 100,000. "But that's just a spin off game from the TV show."
Compare that to Spongebob games which sell millions of copies. I'm not sure what the newest game is, but you can see that the series has no problem with both a TV show and games. But Pac-Man can't. Now let's compare the Pac-Man world series. Pac-Man world 2 was released on 5 systems and sold about 2.48 million copies. Sonic Adventure 2 (released around the same time) was on two systems and sold 2.68 million copies. Look pretty close right? Well, you have to consider the fact that Sonic Adventure 2 was sold on the Gamecube and the Dreamcast which was dying when the game was released. So, let's compare Gamecube sales. Sonic Adventure 2 sold 2.56 million units. Pac-Man World 2 sold 0.37 million. Pac-Man world 3 sold 0.67 million. Sonic on the PS3 sold more as did Sonic Riders, which was a spin off. You can see that the Pac-Man series has struggled and the reason the World games did OK is that they were put on every system possible and rode the waves of a good economy. Every other Pac-Man game that was not based on the original or Mrs. Pac-Man did awful and worse than what I mentioned her.
There is this silly notion among Pac-Man fans that he is very iconic but that isn't showing up on the sales charts. Even Sonic, who had arguably bad games throughout the mid to late 2000s, sold consistently better than Pac-Man. In order to understand the decline in the series, you have to understand the series. Pac-Man was originally designed for a female audience. The guy making it wanted to make a game that appealed to women, and he thought women liked eating, so Pac-Man as born. Afte Mrs. Pac-Man, the series declined. Namco tried to make him a character to compete with Mario and Sonic and make games like Pac-Man Land and Pac-Man 2. It's safe to say that none of these caught on and the series never did well. Sales for these games never broke 2 million sold. Again, if he was as iconic as people here try to make him out to be, where are the sales numbers. The series now appeals to kids as a substitute for Mario and Sonic. Also, consider the fact the the series goes dark for a while and then pops back up to go dark again. There wasn't much done with Pac-Man till Pac-Man Wrold. After the series went bust, it went dark until the cartoon. There may have been side projects, but nothing along the lines of a main entry. Pac-Man declined because Namco tried to make a character where there was none. Pac-Man was not a character like Mario. He was a circle who ate dots. When Mario Bros 3 and Wrold were released, they were still platformers. When they went to 3D, they were still platformers. Pac-Man was a maze game that the company tried to turn into platforms. Since people didn't buy Pac-Man for platformers, the series went to hell.
Some good points, and I won't fight with you too much here, but I do have a couple things I want to go over. You say that Namco hasn't tried to create a unique universe for Pac-Man. Therein lies the problem. They HAVE tried. They're trying right now. The Ghostly Adventures television show is unique, fun, and pretty inventive in its own right. The characters are new and differently designed with personality and backstory. Is it 100% original? No. Is it something new? Yes.
But here's where we get to the problem. People consider Pac-Man to be so iconic, even if they don't consciously know this, that they are actually against the idea of change. Namco is trying to rebrand the character with a new universe, one that has few ties to the maze games of old, but people still stick to the classic. You don't know how many people I've seen watch the new show or see the new games in action and go "why does Pac-Man have legs? Why is there a city? He's just a ball that eats dots in a maze! This is stupid!"
Ignorance and refusing to accept change are, unfortunately, a running theme with Pac-Man because of how incredibly iconic he is. He is the grandfather of video games, the game that spiced up the arcade scene far before Mario ever did, and it wasn't just because it appealed to women. That helped, but that's not the main reason. It was a fun, unique, amazing game that no one had ever seen before. Everything up to that point was alien shooters or tank shooters or plane games. It was all stuff we see in every day life or on television, but Pac-Man was something completely new and inventive. That stuck with people, which is why it's considered
the most popular arcade game of all time, grossing $3.5 billion during its time. If you look a little further down, you'll see
Pac-Man is rated the most popular arcade game of all time, easily beating out Street Fighter, Mario, and Mortal Kombat by itself, not including spinoffs. People loved it so much that Pac-Man has been around for more than 30 years and people STILL play the original game. Hell, I'm willing to bet you people still play the original Pac-Man far more than anyone plays the original Mario Bros. or even Super Mario Bros. nowadays.
Combined.
I unfortunately can't find sales numbers to do it justice like you did for the Wii U and 3DS sales of the new Ghostly Adventures game, but looking at the iOS app store reviews for Pac-Man, it has
over 17,500 reviews. That's a lot, and that's not including the amount of people who simply downloaded it and never reviewed it. Considering each of those people who reviewed it bought the game at it's current price of $2.99, that's over $50,000 in sales from a small app, and again is not including the amount of sales of people who never even reviewed the game, which, when it comes to app store stuff, is the greater majority of people.
Do you see what I'm getting at? Pac-Man may not be as popular now as he was then, but he still holds an incredibly important part of history and a special place in people's hearts. Pac-Man fans may not be as numerous as Mario or Sonic fans, but we're still here, and we still enjoy this character we've cared about for years because we recognize the importance of him to gaming culture rather than just looking at sales figures and numbers. You're looking at current Pac-Man. We, the fans, are looking at him as a whole, his history, his importance to gaming, and his legacy, be that what it will. Fanboyism speaks for a lot of things, as does antifanboyism. I personally don't understand why people like Gears of War, and I could go on and on about how I find it boring and dull, but I don't because I understand how its unique take on arena shooters paved the way for many solid games that followed it. It's not my favorite title, but I don't deny its impact. Iconic doesn't mean sales. It means memorable or remarkable, and Pac-Man has been that.
As a final note, I do find it slightly insulting that you'd consider Pac-Man fans to be children. I'm 33 and have been a fan of Pac-Man since I was a child, and have grown up enjoying his continued presence in gaming. I imagine Pac-Man fans to be a wide range of ages, from those who grew up with the original games to those who are just now being introduced to him, and the fact that newer kids are finding him entertaining enough on TV or in video games to go online to a forum and put in their support to get him into Smash Bros. speaks loudly about how he can still appeal to all ages.
And hey, I found my old account here on Smash Boards.
Made back in 2002. Was a Pac-Man fan back then (obviously by the username) and still am today. :D