Nicely put, Jellykitten1.
I don't think the OP put her point at all well, but I can see (some of) what she is saying. I once passed a parent going into DS' school telling his child 'Don't worry about it - all the teachers are shit anyway'.
I think there is a small minority in society (from all ages and classes) who make everyone's life a misery with their selfish attitudes.
One example is the father who takes his children to the local playground and, despite numerous 'no dogs on the park' signs, allows his vile mutt to run around with no lead, yapping at the children's heels. When my DD (3), who comes screaming over to me, he complains that 'it's only being friendly'.
Another example is the rude (old) woman at the bus stop who tutted loudly behind me and virtually pushed me over because I was, outrageously, letting the people in the bus queue get on before me rather than barging on. Her reply to me was 'I'm cold'.
It's the 'Im alright, fuck everyone else' attitude that make many people's jobs - whether they are teahers, nurses, shop assistants/managers, flight attendants, hotel receptionists etc - just that little bit more difficult than they need to be.
It may be good fun to vent at the OP for her unfortunate way of putting things, but I can see how frustrating some people could make her job.
Luckily, I have only come across one truly vile parent - they happened to be a deputy head at another school.