Katie was a whole lot smarter than Ben. And wittier.
There's something almost (but not quite) endearing about how dumb Ben is. He has no tactical awareness
whatsoever. As Suralan has noticed, he's insulted everyone. Good luck to him trying to get a favour out of Kimberley after calling her obese.

He's too stupid to cover his back. Last week he banged on and on about how great his product was, even when everybody else saw it for the 'fitness box of crap' that it actually was. A smart apprentice would have gauged public opinion and searched for someone else to pin the blame on. Not Ben.
Plus the braces are ridiculous.