Uhhhh...... I mean...... okay, I'll take your research as gospel.
So what?
That's still more than TWICE the salary of the average college graduate. And for what, for teaching 18th century Greek art? Gimme a frickin' break. It's insane.
You're missing the whole point that a full "professor" isn't an entry level job... Why should a recent college graduate make what someone with numerous years of experience is making (in ANY field)? What's the point of even comparing the two? The average Sr Director at company XYZ is going to make a heck of a lot more than a recent college graduate as well. So what?
I'm certainly not going to say every professor is worth it. But when you're talking about an average, that's including some of the science and engineering fields and not just "18th century Greek art". I'm perfectly fine with paying 100K plus to an engineering professor that knows their shit and has been teaching for years to get to that point.
Now if you want to compare tuition vs starting salaries of graduates to show how ridiculously excessive tuition is, then I'm all on board with that.