Gotta chime in and say 3.X is much closer to OD&D IMO than any of the other versions, including 1st Ed. Most of the grim fury that is adventuring is back, and not as much time is spent calculating and recalculating bonuses and such. It brought the game back around to players caring about the adventure they were on, not their magic/steroid PC that they have created to be competitive with everyone else. Once again it is becoming a team oriented sport, where each component is appreciated but not overwealming vital.
That said, if they want to go back to 2E, just add more rules to you 3.5 game to take a PC's eye color into account for a bluff check and some other unnecessary tweaks that 2E players seem to just love. Ask them if they have ever played OD&D and if they liked it. Chances are they want a different type of game that rewards the players by adding to the PCs, not progressing in a story or doing cool actions. I like to escape those groups as those players are not the type I want to game with. As you can tell, I like to have plots that progress, storylines that reveal themselves as the players unlock certain clues, and baddies that have motivations other than just slay the PCs cause they showed up.
To me all of these issues were revolutionized with 3E vs. 2E, and brought the game around from appeasing twink-maniacs to inspiring imagination once again. As a DM, if you don't like the game system, no prob, run your own. Leave my choice to run 3.X alone, I like it.