Disabling Click-To-Move would be a good idea from a bot standpoint, because even though it won't eliminate the bots, it would seriously cripple them. The bot programs base all of their automated movement on Click-To-Move. Emulating key-presses as someone said above is highly inefficient and inaccurate to automate for an A.I. (example: trying to figure out how long to press "Move Forward" in a dungeon hall, then figuring out how long to press "Turn Left" to take a left turn)
However, I think we underestimate the number of players who use this feature legitimately. I would certainly support since I don't personally use it, but Blizzard as a company has to take into consideration all types of players as well.