I agree with most of what you say, though I'd like to nitpick because... because I'm on the internet and that's what my internet manual says I should do.
I understand the concern over appearing "condescending, argumentative, or otherwise unpleasant" but sometimes you need to do that. In fact, if I were hiring I'd find such characteristics totally appropriate and valuable, to a certain degree.
I say, sure, be polite but when you are taken to that limit, feel free to condescend, get argumentative and express yourself.
I understand the concern over appearing "condescending, argumentative, or otherwise unpleasant" but sometimes you need to do that. In fact, if I were hiring I'd find such characteristics totally appropriate and valuable, to a certain degree.
I say, sure, be polite but when you are taken to that limit, feel free to condescend, get argumentative and express yourself.