I have to admit, I've never really understood the dislike of roles, other than "Oh noes, it's from video games, it must be baaaaaaad!" Which, honestly, I have no patience for.
Good grief, I don't even play video games and I can still recognize that that MOUNTAIN of analysis that has been applied to how video games work is of great value in RPG design. There are differences between TTRPG's and video games of course. But, there are a number of similarities as well. A number of the basic concepts do port back and forth.
Why wouldn't you want to avail yourself of that analysis? Why stick your head in the sand and try to re-invent the wheel? Or, worse yet, try to prevent the wheel from being invented in the first place.
Roles didn't originate in video games. They might have been codified there, but, roles have their origins in wargaming. The terminology might shift, but the concepts are all right there.
When discussing how a class operates in combat, why wouldn't you use the language that's been developed to discuss how a given class operates in combat despite the change in medium?
The problem comes when people want to do two things:
1. Conflate role with what the character can do. Role talks about combat. That's ALL it talks about. It does not comment in any way, shape or form on what a class does outside of combat. Claiming that all a fighter can do is "defend" ignores the fact that defend has nothing to do with what a fighter does outside of combat.
2. Try to argue that somehow TTRPG's are special snowflakes and not games. That TTRPG's do not share any commonality with other games out there. Unless, of course, we happen to like a particular game, in which case, commonalities are perfectly fine to discuss.
4e's biggest problem wasn't that it focussed on combat to the exclusion of everything else. It really doesn't. There's all sorts of things in 4e that push the game in other directions. Unfortunately, 4e's biggest problem was and is, presentation. You open the PHB see the Wall of Powers most of which are combat focused and presume that that's all the game is about. You see Roles and presume that they dictate how the character must be played.
Roles are no more proscriptive than alignment was. They are descriptive, in exactly the same way alignment was descriptive. But, unfortunately, they're not presented that way and we wind up with these discussions where people are, quite reasonably given the presentation, presuming things about the game that are possibly less dominating of the game than they might be.
4e is a game is DESPERATE need of better presentation.