3.0 was a significant departure away from BD&D and AD&D. And a lot of the changes made in 4e that 3.X fans complain about, such as here, are because 4E returned to D&D's philosophical roots in terms of game design (although focussing more on dragons than the dungeons that had been the mainstay of oD&D).
That's certainly one way of looking at it. From my perspective, though, the third editions merely added a lot of rules to clarify the things on which AD&D was silent, where 4E actually turned around and
changed the rules.
Ignoring the matter of Hit Points for now, consider the AD&D model for commoners - they had a handful of hit points, maybe proficiency with a weapon, and that's pretty much it. If they advance at all, which they by-and-large did not, then they did so as PCs. A gish was a multi-class fighter/mage, and you had to consult the PHB to find out what "multi-class" and "mage" actually meant. The only rules for advancement were PC rules!
So, while NPCs were
described as being different from PCs, they actually used the PC rules wherever possible. It's no surprise that 3E took that to its logical extent, and said that
everyone used the PC rules, which they then proceeded to detail how you could have a level 17 multi-class noble 13 / expert 4. Then, 4E turned that around entirely, and took the original description in a completely different direction - now, NPCs
were as different as they were originally made out to be, and
avoided using PC rules whenever possible.
So I'm sure how you can see that both 3E and 4E have equal claim to tradition at this point - 3E is an extension of the traditional ruleset, in defiance of traditional fluff; while 4E is an extension of the traditional fluff, devoid of its traditional rules.
Or to put that another way, 3.5 was the most extreme form of everything that D&D had ever been, while 4E was the most extreme form of everything that D&D had ever claimed to be.