Yeah I made a mistake, I started out with an IA comparison and then changed it halfway through and I was speaking like a pretentious *** so it makes sense for people to call me out EDIT; I'm Australian so it was also late >.>.
The rest of my point was entirely valid though.
Reasons to disallow AC switching;
~BW wants you to roll alts, BW wants to keep you playing as long as possible (which you can't fault them for they're a business) rolling a new character and leveling them up will consume more of your time, simple carrot on a stick model.
~It would directly lead to a rise in ninja looting in pugs (which would exasperate the 'companion' issue) , although the same argument could be made for duel speccing I guess but the point is it wouldn't help
~FotM rerolls would be crazy; 'omg they buffed sniper engineering!?!?' all the operatives re roll which in turn leads to more ninja looting as they desperately try to gear up their new snipers. Now I'm sure I'm going to get plenty of responses to this like 'I'd never do that' but lets face the truth here it will happen no matter how much indignation we have.
~It will lead to people no knowing there class; Now I'm not in the best position right now to make that call in most people's eyes here because of my fundamental gaffe up above. But Like I said in my first post ACs are different (granted somewhat less so they then could be by sharing some abilities and having the same resource management), part of the leveling process is learning how to play your class you aren't going to get that with instant rerolls.
Do you really want a marauder who wants to try tanking despite never playing it before in marauder gear (trying to get some immortal gear in your pug) tanking for the first time ever with no idea what they're doing?
~It takes away the meaning of the choice; By choosing to play an assassin you chose to play a primarily melee class with some (mostly instant cast proc based spells) with stealth and tanking options, if you want to play a healing spell caster you should have to level a healing spell caster like everyone else who wanted to play a healing spell caster did (and vice-versa).
Great points and I don't think anyone is arguing the important nature of the decision of the AC. I think the point is, if it were that important, why wasn't the content designed around it so that when you DID level up again as the alternate advanced class you would have an entirely different storyline to work through.