I don't get it a ton but I've definitely had enough people comment about little dogs that it irks me. I think what irks me the most -- it's usually people that have "big tough" dogs WHO DO NOTHING WITH THEM. Their dogs are nothing more than a couch ornament who gets fed twice a day. But they're going to make fun of a small dog lol, ohhhkayyy.
We have a family friend who used to jokingly make comments but it was enough that it would annoy me. He IS a dog lover and I know he doesn't mean real harm but it just always amused me if he would make comments about "my little rat" etc (mind you, Jackson is a Westie-sized Yorkie at 18lbs lol) when he had two Boxers who never went for walks, never got out of the house, were not trained at all. Jackson blew his dogs away
I do think I work harder to try to "prove" my little dog than I would if I had a bigger dog. He literally can do all the same things that a big dog can do.