Because it is probably the most common goal of someone seeking a PhD. I know MANY people with PhDs or in PhD programs. Family members, friends, acquaintances. The first time I ever "met" someone who was going for a PhD in a non-science subject for a reason OTHER than seeking a tenure-track position was HERE. In fact, other than for personal satisfaction, I am still trying to wrap my head around why someone would go for a non-science PhD for reasons other than a tenure track position. I can tell you this, while UoP and Cappella may not be well respected PhD programs, at least they ARE PhD programs. You CAN get a tenure track position with a degree from, or enrollment in, a UoP PhD program. I've seen it. Is the university going to be a top tier research giant? No. However, 4th and 3rd tier schools still have some of the sweetest deals for tenure I've seen, and I would be happy to have them if I was in teaching.