My one problem with 4e is that it puts too much emphasis on your role, and less on your concept; in fact, the game basically punishes you if you choose to play what you want and not what the group needs. This alone makes me want to revisit 3.x via Pathfinder, since I would much rather be able to tell my players the theme of the campaign, and let them make whatever their heart desires that fits the theme, than have at least one person who ends up having to play a certain character class because otherwise the group will be without a tank/aoe/buffer/dps.
Play whatever you have fun with, and I'm not going to say that 4E is better or worse than another, however I think that this particular criticism is so off base that it really begs comment.
My personal experience is that 4E is the exact opposite in this regard. D&D has always had roles, they just weren't explicitly stated. In fact, D&D started with classes that only embodied these implicit roles (though with some evolution over time). Most classes that came after the originals were really just more flavors to do the same roles, or hybrids of these roles.
NEVER have I played a D&D game before 4E where people didn't feel like someone needed to play a cleric. Not just a role, but a specific class. Usually the last person to decide on their character, or who was indecisive got stuck with the Cleric. If you picked a healing class other than a Cleric, you usually got to hear complaints and grumblings every session about how they wish they had a Cleric. Now, there are many Leaders to choose from, with different flavors, all effective, and that are fun.
However, not even Leaders are absolutely required. I've seen games with no leaders, with no defenders, and with no controllers. They each had their own challenges, but none of them failed. In fact, unbalanced groups have worked better in 4E than in any previous D&D edition, in my experience.
This is further made true by the divisions of monsters into roles and categories in ways that it's easier for a DM to fit encounters to the party. The DMG gives advice on how to balance encounters when you are missing a role, and what types of monster roles to avoid per missing role. Because explicit monster roles didn't exist previously, this wasn't nearly as simple before 4E.
There may be many reasons to prefer a non-4E system, but this particular criticism just doesn't hold water.
