The hiring and tenure granting to the these worthless people and making their garbage, mandatory classes is one of the main reasons, the cost of going to colleges/universities is so expensive.
Tenure really means keeping the lazy bums who could never get nor keep a real job in the real world.
Many only work 5 hours per week, get the summer and every holiday invented off ( paid ), great benefits like free health care, discounted housing, lovely retirement plans...plus $100,00 per year.
Then then can get book deals, speaking fees...
All thanks to the taxpayers. And they hate the taxpayers.
Don't forget other motivations. Accrediting agencies have been forcing multiculturalism for some time now.
And, of course, universities that care about racial and gender balance (and even though 60% of students are women, "gender balance" means getting more women in the sciences and engineering and racial balance doesn't count Asians of any stripe) figure the easiest way to get it is to have racial- or gender-based areas of study.
Plain old history departments tend to have a lot of white guys.