Jesus, just reading some of the things that bother some people can be such a bizarre experience sometimes... I know this site has its fair share of weirdos but still.

How on earth can someone getting better service than they paid for bother you so much that you actually complain about it? Especially since you weren't even in J. If I'm flying in J all I care about is what service I get, not whether people who are "not entitled" to J service get it. And ok, someone switching seats next to me in Y might get a bit annoying but it's hardly worth a complaint...

Do you also write complaints when they bring a birthday cake if a passenger happens to have a birthday on the day of the flight?