Its a YDI from me. Why is the OP obsessing over such things. Obviously the teacher said youre doing great things..

Because it was obvious that the teacher was trying to come up with something? You don't have to care about your relationship status to be upset and find it awkward that someone randomly threw together a compliment for you and didn't really mean it. Though op: if someone views relationships over actual achievements you made try not to worry about what they think. It's hard, but people are worth more than being someone's girlfriend.

of course it does.

Preach! People act like having a man/woman is the end-all, be-all of existence, when, in reality, it can be very burdensome to many people, particularly if the other person isn't on the same wavelength as you and doesn't understand what you want or need. OP, set your own bar high, and fuck the haters (not literally).

Maybe those students and that teacher are friends on Facebook or some other form of social media.

Why is it considered mandatory to have a boyfriend in your opinion #5? The girl is young, still in high school or maybe just finished. She lives in the USA where everybody is considered equal in front of the law. She doesn't have to be in a relationship to be allowed to study or work. If she feels like a "leper" because she's not in a relationship, then it's her environment that hasn't gotten the spirit of equality. What the hell is wrong with her teacher virtually putting her down for not having a boyfriend? Would have certainly been enough to say "Good to see you girls, how have you all been doing?"

Good advice, too bad so many people don't think like this.

Agreed. If you are doing great things OP, take pride in that. Smile and nod, and keep enjoying your life. Don't let this incident get you down, and don't let yourself get desperate simply to conform to norms imposed by others. You've got this! :)