I didn't have time to refer to this thread for a while, so my apologies for stepping back several pages.
I think we may have a confusion of definition.
I would instead say that tactically they are almost nothing alike. A striker isn't a controller - the results of the use of their powers is drastically different. On that I'll agree.
But mechanically, they're the same. Same power structure, same mechanic for seeing if a power works. The results are different, but the root mechanic - the basic structure of how a power is built, and what a player does to use it - really is the same. That unification and simplification is supposed to be one of the selling points of the system, and is what allows them to balance various classes more easily and completely.
I mean, look back at 1e - the poster child for hodgepodge mechanics. Wizards and thieves used completely different mechanics. One used spells, another used a chart rolling percentile dice. That's what I call different mechanics. Psionics then had a completely different structure off on the side, which might be applied to any character. By comparison, 4e classes really do all use the same mechanics.
The issue at hand is that you can't please everyone - what is a selling point for one person is a drawback for another. Some folks like that similarity, as it means after playing one character, they don't have as great a learning curve when they play other classes. Other folks feel it renders the game kind of boring, without variety.
I, myself, do find the unified mechanics a little lackluster. Maybe bland is a good word for it. I tend to prefer systems where the mechanics you use add to the flavor, rather than remain neutral, even though varied structures inevitably leads to a system that's harder to balance and use. But, I don't think 4e is so dull that I think the system ought to be trashed - I'll play it as readily as any other system. But I recognize it as a place where they chose to make things easy, rather than interesting.