Except you're sitting next to your coworkers - not your boss. Your coworkers don't want to out you - that only hurts their reputation and gives them more work.
If anything, this prevents one person from being singled out because it's difficult to get mad at one person for slacking when everyone is slacking to a similar degree.
At least, that's my experience being in a 4 person cubicle. It built trust between coworkers and against the company.