A lot of situations get more bearable with a little impromptu live music. This is one of them.
To put it bluntly, if I had been somewhere on that plane, I just wouldn’t have cared whether you wanted to hear it or not.
Rules are made to be bent when necessary. That’s a cultural matter, and the question of who gets to bend which rule and when is different from culture to culture. It’s a trade-off between predictability and flexibility. My impression is that American culture is very much on the strict-rules end of the global scale.
They weren’t. At first, they were simply asking about that big peace of carry-on luggage that the passenger failed to stow away properly. They got an answer and then switched to a harmless joke. The joke threatens to fall flat because of language problems, but they manage to clear it up.
And the whole thing is in a place where there is not (yet) a no-humor zone between flight attendants on passengers. I can understand if the situation on United flights has deteriorated to the point where a joke by a flight attendant is seen as a prelude to throwing the passenger off the plane in mid-flight, and where passengers don’t dare to joke because it will lead to being kicked off the plane. But this is not United.
That seems excessive.
I flew from Austria to London with Ryanair once; I only paid about 100€ total, but the official ticket price there was in the single-digit range. Not sold separately, unfortunately.