I'm looking for a word that means: bigotry against, or disdain for, uncouth people. ('Misanthropy' is too general, I think.) This would sort of be the converse of anti-intellectualism. By 'uncouth people', I mean people who (example) might casually toss litter into the street and not give it a second thought, etc.
'Supercilious' is what you are looking for.
"Intellectual snobbery" pretty much fits the bill.
It's a pejorative term for prejudice against people or pursuits who/which are perceived (the implication is, wrongly perceived) as insufficiently intellectual.
An example of intellectual snobbery: A person prefers opera to comic books purely because opera is perceived as 'high art' and comic books are perceived as 'low art'. They find opera more intellectually respectable than comic books. That person is an intellectual snob; they are displaying intellectual snobbery.
Oh, you mean disdain for impoliteness? That's not "the converse of anti-intellectualism". Intellectuals can be plenty impolite (and often are - check your nearest academic listserv for examples).
If you want a word for 'excessive concern for politeness and decorum' then you could try 'fuddy-duddy' or 'prude' (although 'prude' can have the addition connotation that the excessive concern is specifically for sexual decorum).
If the person is excessively concerned about minor rules being broken then 'prig' might work, but it sounds pretty archaic now. The children in the E. Nesbit novels spend quite a bit of time calling one another 'prigs':
"The only thing is - don't you be a prig, that's all. You keep your eyes open and if you feel priggishness coming on just stop in time"
(The Railway Children, 1906)
While not considered neutral, haughty tends to be one who disdains those below him.
I understand that the idea of superiority is not intended but it would be understood that disdain of bad manners would strongly imply a connection between bad manners and the people who would employ them.
'Smug' is also a possibility. It is worth considering at least.