I think Smash 4 would benefit from making a game more like Melee. Not exactly, but closer to it.
If you think about it, Melee sold about 7 million units out of 21 million GameCubes. That's 1 in 3 GameCubes having Melee. It was the best selling game on the GameCube, which makes it the textbook definition of "system seller". Brawl, on the other hand, sold about 10 million units. This is a higher number numerically, but one must consider that the Wii sold 100 million units to the GameCube's 21 million. This means that 1 in 10 Wii owners owned Brawl, while 1 in 3 GameCube owners owned Melee.
That's my argument from a business standpoint, which is what Nintendo is looking for.
Hold up, there. You're making the assumption that because Melee was more competitive this somehow meant that it sold more copies. But here's a few things you should consider:
1: Out of the 7 million people who bought Melee how many people bought it to play competitively or ended up playing it competitively?
2: Out of the 7 million units sold how many people played it as a party game?
3: Out of the 21 million Gamecubes sold how many were bought by a "core" audience?
4: Out of the 10 million units Brawl sold how many were bought to be played competitively?
5: Out of the 100 million Wiis sold how many were bought by a "core" audience?
I'm not mathematician, frankly I got Cs in the subject all throughout High School, but I get the impression that the proportionately lower sales of Brawl had more to do with the kinds of people who purchased a Wii instead of any sort of "competitive VS. casual" nonsense.
I'll be honest, I was about eight years old when Melee came out. At the time, I didn't give a damn about any sort of meta game or advanced techniques. I was more excited for the fact that I could make Mario and Link fight each other. You also have to consider the kinds of kids like that who bought each game.