I come from a world of text-games and MUDs, same idea, just you need to know how to read fast to play. Alts have a lot of valid uses, staff don't use the same char as the ones they go have fun with, or shouldn't, rather. differant RP themes might also warrent it, if you rp enough to justify having a char JUST for that. they can also be good for the market, assuming your buying stuff for all of them... I keep myself to a four account limit, really. which is a personal preferance.
Honestly, I don't like taking things from folks, I know it costs real money to put it there. There's so much free or nearly free stuff out there you don't have an excuse using a premium player as a springboard for one char, let alone all of them. If you don't use it to spy on folks, and you don't use it to break the game, as it where, then it's alright... sadly, most folks don't really adhere to that, which hurts the folks that are trying to be honest about it.