I don't think that's as unpopular an opinion as some people make it out to be. I think some people live in communities or social environments where they feel a lot of pressure from their families and acquaintances and that these people understandably overestimate how much most people care or even think about such things.
I didn't get married until I was 40 and didn't have a kid until 42 and with maybe one exception I honestly cannot remember anyone ever questioning my decision. Even my grandmother told one of her friends, who asked when I would provide her with great grandchildren, "that's none of my business."
Of course, maybe it's possible that I'm the odd one since I've spent most of my adult life on the culturally very liberal US west coast.