This is an uncomfortable truth for many people, but there's a very good reason people use prejudice:
it works. There really are correlations between appearance and behavior. If you see someone in a paramedic's uniform, is it prejudicial to assume they know CPR? Why yes, yes it is. It's also eminently sensible. There's nothing categorically wrong with prejudice when it's built on real correlations. And there is a genuine correlation between airplane terrorism and Muslims.
In this particular case, you don't like the effects that prejudice can produce: namely, you don't like that people may move from thought to action, and treat people badly who don't deserve to be treated badly. I would agree that such a result is a bad thing. But actions and thoughts are
not the same thing. There's a reason that punishing people for "thought crimes" is repugnant. And it's hard to escape the conclusion that what Williams is being punished for here is admitting to a thought crime. At no point did Williams ever advocate
doing anything against Muslims. At no point did Williams even say that the thoughts
he had should be shared by anyone else. The only thing he did was admit to having a prejudice that comes from noticing a genuine (and obvious) correlation. Given everything
else he said (and I'd recommend watching the
full segment, not just the short clip), it's clear that Williams actually took pains to say that he didn't think Muslims in general were any sort of threat.