It's interesting. I had a discussion with my group's DM this past week over the merits of running 2E vs something like Castles and Crusades. His response was that he likes the little bit of extra difficulty in the 2E system, for example, like sometimes having to roll low and other times roll high, because he considers it a filter of sorts: it chases away people not smart or mentally agile enough to handle playing in that sort of game. And after playing in a couple of other different groups with some players who almost literally couldn't add the numbers on three dice, I'm beginning to think he may be onto something.