blacks in baseball

i didn't realize this [because i don't watch baseball], but there are not as many blacks in baseball as previous years. according to this article:

The Astros are the first World Series team in more than a half-century with a roster that doesn't include a single black player.

"But they're not the only ones. There are two or three teams that didn't have any African-American players this year."

hmm... supposedly it's because blacks are going into other sports. i'm not sure i buy that argument.