So, yes, this is a joke. Obviously. You can stop getting angry now. Or get angry, but get angry at what Rent-a-Minority is angry about. The site is a #satire on a type of tokenism that is particularly rife in the tech and media world.
Your remark, on the other hand, not so much.
That's good. I'm glad we can all enjoy laughing at minorities together then.
Your sound like you see yourself as a non-racist, but you probably don't realize that you are actually being racist yourself by making these comments.
Just because black people specifically are underrepresented in SV doesn't mean that it's (racially) non-diverse.