I noticed that backlash as well. I believe the issue is that when a guy is the main character, in general he is from a variety of stations in life, but there's a heavy trend of having female protagonists be princesses or royalty of some kind, either from the start or marrying into it. I guess the idea is that it's gotten stale to reuse the same type of heroine in animated works, sort of like the NC's peeve about how the princesses never become queens. It just gives the feeling that it's a quick and easy way to write out that the girl is hot and has a lot of pretty outfits and has resources and is in the thick of the action.

It's like any trope. If you do it right, it works fine. If you do it sloppily, it feels cheap.