This pushes my buttons, too. How hard is it to use "Ms." when in doubt? I thought it was a safe default. I honestly think some people just never learned this basic thing about manners and how to properly address people.

I've got a slightly different variation of this pet peeve, but I think it's pretty close to yours.

I had a manager who kept addressing me as "Miss HusbandsLastName." He was basically the same age (30-something) as me, maybe he thought he was being cute. It was pretty well known that I am a Mrs., and I let it be known that I felt it was inappropriate to refer to me as Miss -- in this case it felt as if the manager was trying to assert hierarchy in what should be a relatively collegial environment. I told him directly that "Miss" was inappropriate, and if he insisted on not using my first name, he should address me as "Ms." or Mrs." And I was definitely not to be addressed as "Miss Husband'sLastName"

To me, using "Miss" in a professional setting has some mid-century connotations: less or inferior education, supportive/administrative "office girl" status. Kind of like how the women in the office are treated in Mad Men.

I didn't mind being called Miss MaidenName when that's who I was.

I didn't mind in college when an elderly professor addressed everyone in his seminar as "Mr." or "Miss." He explained to us on day one that it was a custom of his generation that he had not been able to shake; it set a formal tone for his classroom; and it actually made us feel rather grown up, at 18-19 years old, to be addressed that way. And to be fair, as a sept- or octogenarian, he probably earned the right to call us all "Miss." I'm sure if there were any married female students in the class he probably would have taken pains to call them "Mrs."

The manager kept using "Miss." Didn't matter that I had the same degree from the same university. Or that in this day/age/year/progressive city/contemporary profession, the norm is to be collegial and simply use first names. At the end of the day it was just one of many things that made me decide the company was not a good fit for me.

Another anecdote comes to mind: I had a teacher in HS, a woman, who had her Ph.D. Her husband did not. But their mail was often addressed "Dr. and Mrs." when it should have been "Mr. and Dr."

People can be really dumb about this stuff.