Having read all the posts I think it is rather useless though justified in some cases to blame the screeners. They do their job and are paid for doing what they told to do rather than to use common sense. The latter would even intimidate their jobs.
However, the politicians who are responsible for these procedures are to blame. Their "no-exception-for anybody" decisions have created all the unpleasant situations many of us have encountered.
Why are there so many differences in security procedures in different areas? Of course Far East is the area which is most comfortable for pilots in terms of being respected while North America, Central America in particular and Europe are less pleasant. However, there are the different rules in these countries which make the difference.
In my judgement the solution could be a world wide standardization only, e.g. a world wide database with biometrical data such as eye scanning which identifies a crew member undoubtedly. Having properly identified there would be no need for crew members to undergo a screening at all which would be justified in my eyes due to the nature of our job.
To blame the screeners is useless as they are working like robots and hiding behind the rules.