a post a couple days ago about Chuck E. Cheese... and also the banality of saving up experience points for some eventual reward. But what he may not have noticed is that his post is an indirect argument in favor of XP for treasure.
Consider this: if you only get XP for killing monsters, or perhaps also for solving puzzles and "good roleplaying", you get no immediate benefit, other than the good feeling you'd get at a job well done. But when you get XP for treasure, you are also getting the treasure itself. Treasure thus has both a long-term benefit (increase in level) and an immediate benefit (spend it on better stuff.)
You could, of course, ditch the XP part, if that really wasn't your thing. But ditching the treasure part is a bad move.