The part of the sentence "it's not polite" is correct and usable in written English.
You can use it to emphasize politeness in a variety of situations. For example, you might write: "Please remember to thank your host for dinner; it's not polite to leave without expressing your gratitude."
As she sang, she stared inquisitively at the house: really stared, as in "it's not polite to stare".
In rural Oregon where I grew up, we were taught that if you've made a huge mess in someone else's living room, it's not polite to denounce the cleanup.
Rubbernecking falls under one of Mom's rules of etiquette: it's not polite to stare, even less polite to stop, stare and block three miles of traffic.
After all, he could be 0 for 0. For all the outs, nobody in Seattle is pushing the panic button, or even paying much attention to Wilson's predicament, presumably because it's not polite to dwell on such things.
It's not polite to talk about money.
Don't ask my "real" name: it's not polite.
Ben Ratliff wrote in the Times that she "looked like an English teacher wearing a sensible black dress with magenta ballet flats" and "stared inquisitively at the house: really stared, as in 'it's not polite to stare.' " Her mother, who was in the audience, heard people laughing.
My mother leaned over and informed me that it was not polite to say that.
I was brought up to know that it is not polite to say 'I told you so'.
Actually, says Pauline, it is not polite to call it a loo, or a toilet; the new posh word is 'lavatory'lavatory
It is not polite to speak of these things; he smiles sardonically, and yet he sees no point in trying to deny the rivalry he has with those who are also his great friends.
