The problem with Brawl is the fact fanboys hyped it up so much with unrealistic expectations, that nothing Sakurai did was going to please them.
In order for Brawl to have been universally loved it would have had to have had over 9,000 characters, with all of these characters 100% unique. If at least 1 of these characters had a move that was in anyway similar to another, the game would have been a total failure.
Oh and it'd have to be 1,000% balanced. I say 1,000% because even 100% wouldn't please the fanboys. If at least one character even has a remote advantage over another, then it means Sakurai is a baby eating Nazi.
Then there's the stages, anything less then 1 million that don't cover every single area ever in a Nintendo game, means Sakurai really caused 9-11.
Oh and finally the music. Every single song ever made through human history needs to be in the game. Of course it can't be the original version because that'd be lazy, but if it's a remix, even if the remix sounds 90% like the original, it's considered rape.
Since Brawl was in development since 1632, with the help of Jesus, Mohammad and Buddha, Sakurai has no excuse for all this stuff not being in the game then does he.