I think it's just one of those general things wherein "I'm doing the right thing, why should someone else be able to get away with it?"
I just don't let it bother me personally but as ~50% of my flights are charter flights to mine sites so I see a lot of people 'doing the wrong thing', ie. wearing hoodies and having their headphones in the whole flight listening to music etc.
I don't think tattling will necessarily achieve anything, in fact it might just fuel some people on to keep on doing it to defy the rules!