this isn't an exploit, gear for other character can be earned on a main character, so it was obviously designed to share across accounts, otherwise you wouldn't be able to get hunter gear on a warlock. Do some research or just play the game before you try to make comments like this that just make you look ignorant. Using multiple character classes to earn gear faster is not an exploit, the only advantage it gives you is raiding a few more time, which is still putting in the time and effort you would normally have to.