Anyone that can only work in a cashier position = you suck.
And I mean that in a nice way. 🙂
Like hell you do.
There are folk at my store who ONLY cashier because they can withstand the barrage of crap guests dish out: the scammers, the uber-couponers, the mom with the screaming kids (one of which just threw up in your lane), the bombastic blowhards who try to intimidate, the ones who leave trash on your belt or hand you gooey toys that they used to entertain their devil spawn, etc.
They'll charm the rudest guests into signing up for a red card, they'll train the un-trainable (after all if you can't cashier, they send you to the salesfloor), they'll help out the back-ups who don't cashier enough to know how to do a tax-exempt purchase, they'll go out to help salesfloor but will ALWAYS come back to cashier when needed.
Yeh, some suck but they'd suck just about anywhere you send them.