I do have a good friend who is an avowed fan of 2e. It's because he learned to play under 2nd Edition, or more specifically, a highly altered version.
Most of the DM's I played under back then had informally collaborated and cross-pollinated house rules. There was a version of AD&D that at the time we referred to as "2.5" (we laughed when they came out with an official "3.5"). This was derived from the core books, PO: Spells & Magic, DMO: High Level Campaigns, PO: Skills & Powers, a lot of house rules (including special techniques for spellcasters, rogues and warriors you could buy with your character points from Skills & Powers that were practically the same thing as feats), and rules for gaining ability score points as you went up in level. Oh, and a multiclassing system that let all races multiclass (including humans), and pick up new classes at any time, or stop progressing in classes at any time. Level limits were gone too. Throw in a few 2e classes that needed to be back in (Monk, Barbarian & Assassin), and a few classes from FR stuff that made sense (Mystic from Faiths and Avatars, and all the Speciality Priesthoods since the games were often FR games).
In other words, the 2e he learned on was 2nd Edition with many of the good ideas of 3rd edition bolted on (or more accurately, independently grown from it). I do think that a lot of the 3e changes therefore were, if not inevitable, the next logical step in evolution (we came up with a lot of them independently, I can only presume that other groups were doing similar things).
He still grumbles that here was no need for 3e (with an attitude of "if it wasn't broken, don't fix it"), despite his friends trying to point out that 2e, as written, includes a lot of things he hates, and what he thinks of when he remembers D&D was a heavily modified version of 2e, that was almost closer to 3e. However, after over 3 years now, he begrudgingly plays 3e (learning other d20 games, like Star Wars, facilitated the conversion since he could learn to play those games without feeling like he was betraying his memories, then when he gets invited to play a 3e game, he already knows most of the new rules).
The point of this is, that 1E and 2E were very prone to house rules. From what I have gathered, no two gaming groups really played the same game. They used the same general books, and called it D&D, but each group/campaign had a written or unwritten book of rulings, precedents, and variant rules. TSR back then wasn't known for being very industrious with Q&A, or errata. Sage Advice in issues of Dragon was really the only way to get an official, or semi-official opinion on anything related to rules.
3E doesn't usually have as many house rules in my experience, mostly because it doesn't need them. It has moved beyond 1E being designed strictly for one specific style of fantasy roleplaying (in the model of Lieber, Vance and Howard, as many have pointed out), and while 2E was more flexible, it achieved it's flexiblity by making each campaign setting have a whole library of changed rules, new systems, and rewriting the game for each setting, while retaining some "legacy code" arbitrary restrictions (the 2E Druidic Heirarchy, for example). 3E included enough options and features in it to allow it to be used for all these genres and styles, without having to constantly re-write the game to create flavor and preserve balance.
3E, and the derived d20 System have proven their flexibility and appeal in all the other games built on it, like the official WotC ones of Wheel of Time, Star Wars, Call of Cthulhu & d20 Modern, and the countless 3rd party games. Just try and make a sci-fi or modern game using 2e mechanics, with it's system of Thief Skills and Nonweapon Proficiencies, and the dual-classing mechanics for humans, but multiclassing for nonhumans, ect.
