What do you think you mean by 'bellcurve of power?' Because, aside from the neat bell curve you by get generating stats with 3d6, I've never heard it applied to D&D before.
More generally, I think it's hard to paint any one edition out of the continuum - though it's really easy to re-arrange it along different dimensions.
3e & 4e are at odds with the other eds in that they're so player-focused, for instance. 4e & 5e are at odds with the rest in that they use uniform advancement of attack rolls. The WotC editions are different in that they use skills. 5e is at odds with all other eds in not assuming magic items will be found as part of advancement. 0D&D and 1e are at odds with all other eds in not having any psionic classes. 2e's handling of 'martial arts' is distinct from other editions'. Etc, etc, etc, &c... ;P
I don't know where to jump back in, this seems like as good a place as any.
2e was designed in part to be backwards compatible with AD&D, although over time it started going beyond that, particularly when the
Complete series came out, and even more so with
Combat and Tactics and
Skills and Powers. Having said that, they were still designed to work with the existing AD&D/2e system, as clunky as it might have been at times.
3e felt a lot like a more logical rewrite of the mess that 2e had become. When the issues with 3e became clear, 3.5e was another evolution. So while there were a lot of differences, they happened in a more gradual sense and a seemingly logical direction, even if you didn't agree with the ultimate direction they took.
And that's the point of the OP. While I think that what the original post considered the important factors in the "feelz" of D&D, 4e broke the mold. It was a bold move, and in some ways I applaud them for that.
5e isn't a return to AD&D or even any other edition. It has many elements of all of them, and a lot of it is new. But the difference (for me anyway) is that you don't quite notice that it's different until you pay attention.
It really is a lot more about perception than anything else I think. There were people who refused to make the switch to 2e, 3e, and even 5e. I think the main difference was that 4e had so many new features and approaches that a larger percentage of gamers objected. I do think it was harder to smooth over the transition to 4e because some things changed so much (like spellcasting and the role of magic items). And there's quite a bit of 5e material that I drop altogether because I just don't care for it. This is mostly lore and certain abilities. But I find the ruleset the most intuitive and easy to modify of any of them. And it feels more and more like AD&D to me, because that's the way I run it.