Sad but true.
UK airport security are about the most unpleasant bunch, bar the TSA of course. One wonders just how these inadequate folk are trained, and what thoughts are put into their heads. Sadly, most are patently unable to exercise discretion, and are unable to participate in wise profiling. I imagine they are at the low end of the food chain in terms of job capabilities.
Blame their trainers and their management; the security people are of low intelligence and need suitable guidance. Their default mode is nastiness to anyone who may appear superior in appearance or attitude, namely well-spoken pilots or passengers. (The dubious-looking ones who may comprise the real danger are always waved through.)
Best say nothing, and show "respect" in one's demeanour. They lap it up.