Why Don't More People Visit Big Bend National Park?

I just went to Big Bend National Park in Texas and think it's a fantastic place to visit. The mountains (the Chisos) , desert (Chihuahuan) and river (the Rio Grande) are so beautiful and educational. Sure, it's over 4 hours of driving from any major town or city, one with a commercial airport (Midland, TX) but the Yosemite NP is 3 1/2 hours away from San Francisco/Oakland or Sacramento and yet it's much better known and more frequently visited. Is it because Texas does not know how or does not want to promote a national park within its borders? California promotes the national parks in its state because more tourists to those parks means more dollars brought in to California.