MF takes more away from the game than it gives. It forces players to choose between power-boosting stats and loot stats. This competition doesn't make a lot of sense.

I think it would be better to force the player to choose between, say, gold stats, items drop rate stats, and item quality stats, just to give 3 random options. The item with (one of) these stats could be a charm (and MF-like stats would not found on any other items). If Blizzard is willing and able to come up with certain "character richness" stats beyond magic and gold find, I could see this working pretty well.

tl;dr - MF should be kept in the game, but it shouldn't compete with power-boosting stats.