Where you forced through the scanner or did they offer you a choice?
As for UK airports. They seem to have a rather inflexible approach as DO AS WE SAY, OR ELSE! Haven't seen them in London City Airport, though.
I could also imagine that Amsterdam only channels US travelers through the scanners. In Zurich airport the US airlines essentially have half a terminal building reserved for their flight operations during the morning hours. I haven't seen scanners there, but flying mostly within the Schengen area I wouldn't necessarily know.
As for UK airports. They seem to have a rather inflexible approach as DO AS WE SAY, OR ELSE! Haven't seen them in London City Airport, though.
I could also imagine that Amsterdam only channels US travelers through the scanners. In Zurich airport the US airlines essentially have half a terminal building reserved for their flight operations during the morning hours. I haven't seen scanners there, but flying mostly within the Schengen area I wouldn't necessarily know.