Frequent SLF, I do take your point. And in my many years as cabin crew, I found that most passengers were conscientious and intelligent about fastening belts and staying seated when the signs came on. But there were also far too many who made a point of ignoring them. As crew, we came in for a lot of abuse if we tried to enforce the signs. The situation was possibly not helped by the hare-trigger reaction of some flight crews, to switch on the signs at the slightest hint of a bump. It's the old Cry Wolf phenomenon.. "But you're walking around!" was a common protest (Protest.. As if by asking them to strap in we were in some way trying to put one over on them..!) I somtimes had to bite my tongue not to snap back, "Ah yes, but we're insured!" It was especially galling with the citizens of a certain famously litigious country, whom we knew would be the first to rush bleating to a lawyer if they were injured; we sometimes wondered if that was the whole point.