Pandora I don't quite see what you are getting at.
As far as I'm concerned this thread is entirely tongue-in-cheek and we are all just having a laugh. I wouldn't really rinse their cup out in the toilet bowl, it's just a tactic I use to keep the cheek in check.
Flight crew and cabin crew do perform very different roles, however why does that mean we can't have fun and a laugh with each other at the same time?
There's a time to be serious sure, but having a joke about a cup of tea at least in my opinion does not degrade the cabin crew role of safety professionals.
Chill.
SG