(Typo: Bount = Bound.)
Otherwise each of our characters will have to buy one (Those who prefer to use one bag rather than just switching over the medium ones, even the large ones. I am refering to the Gargantuan bags.), and aside from Turbine making their profit, that's really annoying to take out ingredients, put them in the other bag, replace bags... etc...
Besides, I bet that if they were bound to account, much more people would buy them. Turbine win, players win, everyone is happy.