Yes, some childless people are rude too, it’s only fair to say that as well. The dental hygienist was rude, sure, but I think it was supposed to be a joke.
I say if you have 7 kids, more power to ya! But, if you say that everyone should have 7 as well, and if they choose not to they’re sinners or something, that’s wrong.
Not saying YOU do that. Just reiterating the point. The reverse is true also as you point out.