Pre-WOTC D&D is definitely easier for the players, for the reason you state. In my experience, pre-WOTC D&D was also many times less stressful to DM, because the rules were a hodge-podge of unrelated sub-systems. If the DM forgot an official rule, it didn't really matter. He could make up a new system on the spot, and know that it wouldn't adversely affect any other part of the overall system. Don't like the weird unarmed combat rules? No problem, just let the players strike as normal and only do 1 point of damage + their strength modifier. It won't cause problems anywhere else. The players were not expected to know the systems the DM used in any event, so the DM was less concerned about rules lawyers. No matter what the DM was doing behind the screen, it might all look the same in front of it. AD&D looks very complicated on paper, but it can actually be played very light if the DM wants to reduce his workload. That's the advantage of non-unified, non-interlocking rules. Of course, such a system does not allow for things like "rules mastery" on the part of players, but I personally consider that a good thing.