Well, my sister is named Linda and she says she hates her name because it dates her. No, it's not the end of the world. Yes, it's very far from the worse thing that can happen to a person. Very very far. Yes, Linda is still an ordinary, well-adjusted, happy person.,
But the fact is, most of us hope that our children will like their names once they're grown, and and picking an overly popular name can be (not always, of course) an impediment to that. It seems overblown on the board, but this is a name board, and when people are on their computers on this board talking about their interest, names, that's what their minds on and so they may tend to get somewhat hyperbolic, but I don't think that they leave their houses and immediately start talking nonstop to all their real life friends about their favorite name becoming popular. I know that I rarely talk about names IRL, and on those rare occasions, only to my daughter, who shares my interest, though not quite as intensely.
That said, speaking as the mother of two popularly-named kids, one named knowingly and one not, I agree that it's not as bad as the OP seems to think it is.