I don’t think it’s intentional, but there are way fewer blacks in MLB than say in the 70’s. Maybe football and basketball are just more appealing to black teenagers. I remember it was a big deal when the Pirates had an “all black” team on the field.
No "maybes" about it -- that's precisely what it is. And there's nothing MLB can do about it. No league or entity can force kids to change their preferences. It's a cultural thing.
Maybe blacks are just not as good at the game of baseball as whites and spanish/native S Americans. Just because they are great at basketball, doesn’t mean they are the best at everything.