The list of bugs I mentioned, which everyone here is already aware of, were partially or wholly fixed in 4e, (or new to 4e which didn't exist before) after many years of people complaining about them. CoDZilla, Fighters being lame at high levels, wizards not having at-wills : those were all "fixed". But, were they fixed in the right way? IMO, no. They went too far. They went with a "paradigm shift" mentality, which threw out the baby with the bathwater and created a game that at the table feels completely different and loses its essential nature. They tried to codify every little thing that could possibly occur to you to make your character do, and if you don't have a power or a feat to do it, you simply can't without a house rule (because otherwise the guy who did take it will complain : hey, not fair). D&D doesn't need such restrictions.
Take Luke and the Rancor pit. In 4e, hitting the switch to bring it down on it might be a feature of the "encounter", in an explicit way. What if there are no "big shiny buttons", but the player comes up with something creative to kill a huge beast in one move? That should, realistically, undoubtedly, simply work. We did many such epic things over the years...and those ideas, as well as the outcomes, are what makes the game fun and exciting. I don't want a narrative where I can try to re-roll five times in a skill challenge to shut the pit door down on the Rancor, I want to come up with the idea on the fly, roll a thrown rock attack on it, and if I fail, mayyybe I can try one more time from the other side of the room, but if I fail? I die. Too bad. The D&D equivalent to that is a "save of die" or "kill or be killed" mantra, quick, brutal, combat resolution. The only way to not die is to not get caught by the Rancor, or stick a bone in its mouth, or something. Tell me, how would sticking a bone in its mouth occur to someone who's grappled? Why not just blast your Jedi daily on it? There was almost always the option to win by mere damage. When you're expected to win, the entire game shifts way too much in the PCs favor. When you're expected to mayybe win, or die trying, but have fun taking risks and seeing what your clever ideas vs the dice have to say about it, then you can see why I want my Rancor pit to be a place where PCs are sentenced to die. If you're down there and miss the button, it'll get a chance to grab you again, and what if you don't have a bone in your hand this time? That trick might work the first time on it, but not the second.
A Jedi's daily is probably the best way to kill this thing, so ignore the bone in the corner over there, and ignore the button too because if your dex sucks you have no chance of hitting it anyway, and in those modules they never make it so only one type of class can win. At least I've never seen it. What I'm saying is, the D&D equivalent to the Rancor pit happens often, in all editions, but without the expectation that PCs aren't immortal and their toons are expected to dust it off and go on to the next encounter (and thus, pay their subs at DDI or the next splatbook). I want PCs to die. I do like a lot of what 4e tried to do, and they've learned the lessons of the past I think.
E.g. the regeneration healing mechanic proposed for everyone is a beautiful, elegant, logical, and natural way to progressively heal. It's better than any edition has done before for most characters. They can instantly reunite all editions fans with a bugfix that kills "Surges" AND allows DMs to keep the adventuring day going forward at whatever pace they want. It's brilliant.