Data point: the DMV here in Montata is staffed by happy cheerful helpful employees.

Quality of interactions with basically all government seems to correlate inversely with local population density.

I had nothing but good experiences with the DMV when I lived in North Dakota. Walk in, no wait, cheerful employees, walk out ten minutes later with a renewed driver's license.

Minnesota is the complete opposite. Walk in, wait an hour, every employee hates their job, then wait a month for the new license to come in the mail.

Are they unionized?

Weird! I've found them to be completely opposite. Trader Joe's employees are extremely friendly and helpful.

Costco employees, honestly, not helpful at all and almost always disdainful of being asked any question. I guess that's not their model.

I suppose Costco employees can be happy with the company, but not happy and friendly to the customers, in which case, that holds up.

They are happy because the company treats them right. Give the DMV people the same rights and perks and you'd see them happy as well.