Originally Posted by
SocietyFlyGirl
Why do some FAs see all passengers as a threat

Yes, 9/11 happened

but that doesn't mean passengers on planes are any more likely post 9/11 to be nefarious, evil-doers. In truth, with all the added security, planes should be safer than before 9/10/01. And really, is a terrorist going to swear about a gate delay?.
I think you've taken it a bit out of context there. This has nothing to do with 9/11. Just because someone is arrested doesn't mean the flight attendant thinks their a terrorist. It can be for a range of reasons (trivial as some of them may be) such as being abusive, drunk, etc. The FA in this situation - in her view thought the OP was being unruly and warranted a police escort. I'm sure the thought of him being a terrorist didn't even cross her mind given that the flight had landed anyway.