It's not really like they "had" to buy more cd-key, it's more like they have more money than other to buy more cd-key.
And it's still a choice not an obligation.
Thus it's not fair fot ppl that have multi char (we can even say that they "had" to have several char to test and enjoy the mod ;))
If someone paid twice for the game, why not? Not like you cannot do the same, is it? Some guys got more accounts purely for trying out STFs, some for whatever other reasons there might be. Still, it was your choice to stick to one cdkey. I am thinking hard to come with some good comparision for this...but meh, failing at it.
Anw, i am speaking as a guy who played SINGLE char for 18generations, made some alts in the process, mostly stf to try out different builds, but deleted them again, so i keep boosting the one and only char i love so much
The problem is, people want to have everything for free. They want to try out new builds, but without losing XP by respeccing or even retiring.
A little derail over here, sorry.