ATS,
With regard to the "class of the majority FR pax", aren't you over-generalising somewhat?
With regard to "what they leave behind", have you ever seen the state of a "legacy" carrier's premium cabin once the passengers have disembarked?
Please don't misunderstand me: I think cabin crew should not have to put up inconsiderate, ill-mannered etc. passengers.
[By the way, I'm the one who greets you on boarding, sits in 33C or D, listens attentively to the safety briefing (even though I've heard it countless times), offers a polite "No, thank you" when offered the menu, and if first in the queue to disembark - which is often the case - will chat to you!]