One reason may be that they have bought the B.S about baseball being a "white man's game". So, they stay away.
Minor leagues.
A player drafted by the Milwaukee Brewers (for example) could expect to spend four seasons at places like Helena, Montana, Appleton, Wisconsin, suburban Raleigh, NC, Biloxi, MS and Colorado Springs.
Compare to up to five years treated as a god on a college campus before the NFL or NBA.