Politeness is heavily under-appreciated by most near-aspie geeks like me.
In reality, politeness serves to make the social machinery operate well, and the cost of being polite seems to be, 95% of the time, swamped by the value in goodwill that it generates.
Cases, however, when politeness MAY not be useful/as useful:
1. near-aspie geeks
2. mixed cultures -- Russian politeness rituals are different from ours, and so the purpose of politeness (ritualized recognition of other's value qua person) is lost.
3. near-mixed cultures -- Texan hospitality and California hospitality are different. Polite in one state is often uncomfortable in the other.