I'm glad you spared me the meme answer because I'm genuinely curious and serious. I could see how sizeplay would be considered normie like the tall lady from the new Resident Evil has proven but not ageplay, especially not /ss/ where the age difference is "real"
In ageplay stuff between two adults, daddy dom/little girl is considered more normal because of gender norms while the opposite is seen as extremely weird and nowhere near DDLG's popularity. Simply put, daddy dom/little girl is more mainstream than mommy dom/little girl, and less frowned upon.
If talking about hentai and such, in most /ss/ works what happens is just as illegal as loli stuff and a guy who admitted to be into /ss/ would be seen as just a different type of fucked up person, maybe less dangerous but just as perverted. Of course, a girl into it would be ostracized too, don't know what people would think of a girl into loli stuff.
I don't know, I don't get why they get so angry about it. It's stupid.