No, but that's not an argument against MCing nor against designing new classes with MCing in mind.
A player wanting a tougher warrior than a Warlord, but more support capability than a BM could play a Bravura Warlord/BM Fighter, one wanting a bit of magic and emphasizing inspiration more broadly could play a Bard/Warlord w/Inspiring Leader, one wanting a very clever tactician might go Tactical Warlord / Mastermind Rogue. Etc...
Well, they can combine existing classes in various proportions, but that's still a long way from 'whatever they want.' ;(
Like feats, MCing helps with customizeability, though even with both, if your bar for 'anything you want' is 3.x it's barely in the same ballpark (and if your bar is Hero System, it's not even in the same state as the ballpark).
Of course, if you're new to RPGing, it may still seem like quite a lot - to the point that no feats/MCing could be easier to deal with, or even that the 'big 4' could seem like plenty of choices...