You are right. It is absurd to deport someone for carrying boxcutters aboard an aircraft. The idea of banning anything with an edge is absurd. This is political correctness gone insane. 9-11 didn't happen because hijackers carried boxcutters aboard an aircraft. It happened because we followed the victim compliance policy: Don't resist, give them what they want, leave it up to the Authorities.
A 9-11 type attack can not happen again because passengers and crew will not allow it to happen. This guy wasn't trying to sneak the items aboard. If you read the case, it is clear that he just didn't think about them because they are such innoculous items. Anyone who wants to can sneak cutting implements aboard an aircraft. The current rules are just image, all for show, and have no real security effect. Their ownly real effect is to make Americans all the more cowed and willing to accept higher levels of official harrassment.
You obviously don't know much about this case, or there is another conclusion to be drawn that I am too polite to post. This guy had very carefully concealed the sharp items inside toiletries (IIRC it was a liquid soap bottle and a deodorant bottle, or something like that).
This wasn't a case of a clueless fool who doesn't fly much carrying items onboard that he thought were innocuous. It wasn't a case of someone who unknowingly left an item in a carryon bag that gets daily use for some other purpose, and had a prohibited item in it. This guy knew exactly what he was doing, and that doing it was prohibited.