But a core part of being polite, is not hruting others through your actions directly or undirectly. ( or at least trying)
In cases where not asking the question puts the other party in a disadvantage or at the risk thereof, I feel one shouldn't be allowed to claim that one was being polite or "doing the right thing".
You were being either too shy, cowardly or selfish. This doesn't mean that you must ask such questions/ venture in those topics. But it certainly does mean, that those that don't, shouldn't be allowed to claim active virtues ( to others or to themselves).
* Also, if one chooses to not inform the other party of the problem, I feel that one shouldn't make them suffer for that choice. Which means at the very least, not trashtalking them behind their backs for it.
The first part is about being good, the second part is about not being actively evil.