damn near every rpg game around has a way to run 2 copies of a game on 1 cpu,as long as you have 2 keys,most legal ways involve user account swapping or multiple machines,most people dont have 2 comps at their desk,and user account swapping doesnt work to well when your rushing etc and dont have the luxury of a 20-30 second swap time.
guildwars for example allows the use of a 3rd party program for running 2 copies,blizzard doesnt allow it on diablo because runnign 2 copies of the game is pretty much a need unlike alot of other games where all your chars share an enormous stash.
and the fact that d2 games crash in the blink of an eye.so self xfers are risky
so the reason behind it?
option 1:blizzard wants you to get banned and buy more cd's
option 2:the community in itself has kinda fucked themselves over with 80% of d2loaders being used for bo barbs/chant sorcs/sage druids in pvp(among other bm tactics)
option 2 is probally the most likely reason why 2 copies arent allowed.
as far as giving everyone back their accounts,most of those names have been remade by now so it would be pointless anyways(mine included)
then again blatantly breaking the rules and getting your gear back wouldnt exactly teach anyone to have accountability would it,i was banned and can say that,so as not to sound hypocritical.
dont get me wrong i would love to have my old 3 socket cruel cryptic of quickness back

not like the ban was a huge surprise:P