Ergo it is a disingenuous question, and/or the person asking it is a blithering fool. QED.
Bill Cosby, for example, never gets asked why white people are under-represented in his show, nor should he ever be asked. What a stupid question.
BTW; I had watched Cosby’s shows (including live action – the cartoon came later) on TV since I was a little kid, and I never knew he was black until I heard someone say so. It surprised me, in a way. That happened when I was entering adulthood, so my “ignorance” lasted through quite a few years of watching him. He never made an issue out of it, so I never noticed. The Cosby Kids cartoon showed kids just like us and our friends, doing crazy stuff just like we did. Same with Sanford and Son for the most part. They were a fairly typical father and son, much like the first-generation European immigrants and their kids that I grew up with in my home town.
Now you get crap if you don’t tow someone else’s agenda line or something. So ignore the crap and mind your business– It’s not that difficult, as Seinfeld points out..