My child is small - why do people feel it's okay to point it out?

My child is really small for his age, he had some medical issues at around 10 months that helped slow the physical development (perfectly healthy now!) And my wife and I aren't very tall.People love to point out how small he is. They will ask his age and be like "wow, he is so tiny or so small" sometimes right in front of him like he doesn't have ear no feelings. I know this bothers him sometimes. Other times he says he doesn't care. But why is this looked at as okay and common? If someone's child was heavy set, you wouldn't hear another parent say, "wow your child is really heavy or really fat". At least your child can lose weight, I can't really make my son grow 5 inches overnight.Sometimes I want to reply rudely but don't, but I wish people would consider that it may hurt his feelings just like anything else someone would constantly point out about another child.Thanks for reading my semi-rant. via /r/Parenting https://ift.tt/2wQZZ8O