Alwaysairbus,
The point is that after 5 year CRC checks on UK nationals ONLY working at UK airports (and in the near future DNA records and biometric ID cards) aviation professionals are required to go through the same degrading experience every day, sometimes numerous times.
Where do we then draw the line? Pilots, crew, ground staff, engineers, caterers, cleaners, fuelers, who should get screened and who shouldn't, who do we consider "professional" and beyond intentionally interferring with a flight?
Checks done for ID cards don't weed out the terrorists as generally terrorists don't have criminal records. More worrying are temporary ID cards issued to new starts, short term employees and contractors etc ... no police, employment checks etc. Around here that can take up to 3 months and all the while that person has access to aircraft!
I think the word "degrading" is a bit melodramatic, that's the sort of thing a pax who hasn't flown for 10 years uses, not a regular who knows pretty much exactly what's expected. But I don't deny it can be an inconvenience and irritating.
I do get your point about an engineer or pilot being able to bring an aircraft down and so too can a caterer, etc..