I disagree with you on what the original D&D classes did. Even in 2e there weren't really skills, and the NWPs were actually mostly given to the INT classes preferentially. So the breakdown was Fighers were ONLY good at melee combat (and maybe STR based ability checks, assuming your fighter was strong, something that was far from guaranteed). Thieves good ONLY at backstabbing in combat and had a narrow group of 'sneaky thief' skills outside of combat. They certainly weren't skill monkeys. The 2e bard was basically a thief that could cast, again not really a skill monkey though his bardic musical/lore abilities make him somewhat of a know-it-all. Clerics ONLY head and buff, with a few specialized attack spells that are rarely taken because they waste precious heal slots. Wizards get all the NWPs AND all the best utility spells. Druids are not bad, but they are not nearly as good at healing as clerics.
4e fighters can focus on damage, but you can also just make a different character that is a striker or near-striker (avenger, slayer, barbarian, ranger, BRV fighter, tempest, or many of the two-handed FWT fighter builds). However 4e fighters are less one-dimensional and weak than previous e fighters. Rogues work EXACTLY like AD&D thieves, except better. Clerics again are much like 2e ones with heavy healing and some rarely used spells moved off to the ritual list. Wizards are definitely less completely overpowered in 4e, but what can you do?
I'm not saying 4e characters are JUST LIKE 2e ones, that's patently not true, but I don't see where they have radically different roles or capabilities. In fact you can make a wide variety of 4e characters that simply can't exist in 2e (at least not without delving far into the later and more questionable supplemental material). 3e allows for most of what 4e does, but comes with some really serious issues and STILL has effectively some of the same limitations that 4e doesn't.
You also have a wide variety of characters in 2e that 4e doesn't do very well, especially specialty clerics -- a character that focuses on buffs/debuffs, for example which really isn't a Leader or Controller. Other difficult to emulate characters include a character that literally can't fight or a divination specialist that has very few combat options.