Because she isn't. You wanna know who is the main character of Star Fox? Fox Mccloud. If she was a main character, she would have been in
all the games in the series as a playable character. Where was she the last 2 games? Where was she for the first 3? Fox is the only one that is in all the Star Fox games and they are centered around him,
not Krystal.
Even Daisy fans aren't that far gone enough to think shes a main character
if they weren't iconic, Fox wouldn't even be in the game lmao. Its almost as if you want zero reps for Star Fox when you make a comment like that. Star Fox 64 outsold every game Krystal was it. For you to downplay that, seems petty
you can subjectively say that you enjoy the Star Fox games Krystal was in but saying Star Fox 64 didn't make much of an impact? LMAO. We can say the Ice Climber series is irrelevant and no one talks about them anymore too but they did plenty for Nintendo back in the day, so they deserve their spot. Sakurai knows that.
You obviously don't know the difference between main protagonist and main character. Fox is actually the main protagonist whereas his team members (and that includes Krystal) are all considered main characters of the series. Even Star Wolf are. Look it up on the wiki.
When it comes to Katt, she remains a side character, same goes for Bill. Reprising a role in a remake of a game you are supposed to be in anyway doesn't make you relevant in the overall story. In fact, if we take all the canon events of the series (Lylat Wars, Saurian Crisis, Aparoid Invasion, Anglar Blitz), Krystal appears in the majority of those (even if we count SF2). The problem is that almost half of the series' games cover the Lylat Wars with only the original being successful. 64 3D didn't do too well. It's funny how people say that Assault did poorly while it actually did better than 64 3D (not much better though, in all fairness). Adventures sold better than 64 3D and Zero combined. 64 was a big thing back then but these days it no longer is. Otherwise its remakes would have done
much better. It's time to take the series to the next level by adding aspects that are popular these days, not 20 years ago. Open World would be a good approach in order to get new people on board.
Don't get me wrong, I like Katt, especially in the comics. I actually like all of the females in SF and I think the next game should include them all, just like SF Event Horizon (cool fangame, you should check it out). I still think that Krystal is way more popular than Katt. I mean look at all the fanart, fan mods and stuff like that. Not even Fox gets as much. I know there is a huge portion of inappropriate fanart but that's what the internet is doing to attractive females, including Katt, Miyu etc. There is still lots of cool fanart for her though, and that seems to come on a daily basis. This kind of devotion is almost unheard of, especially considering the fact that she's been away for
so long. Also, Krystal actually appeared in Smash, unlike Katt and the other females, plus she was playable in every SF game she appeared in while Katt was only playable in Command.
You also said that Krystal is not relevant among the general public but it seems like the series as a whole is not too relevant anymore either. Is there another character from the series that you think is still relevant these days, especially after the failure of Zero? I don't get your point here. The games that feature Krystal actually didn't do too bad, except for Command. Nintendo can consider themselves lucky if a future SF title ever reaches the numbers of Adventures. The 64 remakes failed compared to the original, Zero especially (being the worst selling game of the series). People are tired of the 64 story and want to see something
new.
I have to agree with you that Krystal's inclusion as a playable character in Smash is very unlikely since she has been absent for so long, due to the fact that all we've got in the past decade are 2 remakes of the same game (Zero is NOT a reboot, btw. Look it up). With franchises like Splatoon and ARMS it just wouldn't make sense to add a Star Fox newcomer. She has to return to the SF series first and that shouldn't be too hard if we keep the support coming. It should be easier than getting her into Smash, I think.
The SF series can thrive once more if Nintendo stops making remakes. The story needs to progress once again, something that hasn't happened in 11 years. While the sales indicate that the series is no longer relevant, I think the basic interest for it still remains. If you look at the number of views for 'The Battle Begins', it seems like people are still interested in the SF universe but they don't buy the games. I mean, compare the number of views for the anime with the number of people that actually bought SF Zero. That's another indication that something has to change with the actual games. Not to mention that the anime was well received, unlike Zero itself.
We are all in the same boat. We want to see Krystal again or at least see the SF series becoming more popular. So let's come together instead of arguing and dwelling on the past, and show Nintendo that Krystal & Star Fox support is still strong these days!