I am a math professor. This phenomenon of lengthening literature reviews doesn't exist in math, nor indeed have I ever seen mathematicians assign pointless busywork to sabotage others, or to inflate our own importance, or for any other reason.
Now the intrinsic value of research math as a whole may be debated, especially that of the bottom 90% of researchers (and I would not say I'm in the top 10%).
But I have really not observed math professors to be guilty of what you claim. Quite frankly, math itself is hard enough; there's no point in setting additional hoops for students to jump through. It would just make us look foolish, and waste our own time (in addition to that of others).
Well, pointless busywork was a staple of my high school and under days of math. Once I got to college, I had a professor for Calculus I that said our grade was the four tests + the final or just the final - whichever grade was higher. Having taken Cal in high school, I just showed up for the final and got a B+ (I reversed the damn derivatives of ln/e).
That was the best math class I never took. To be fair, my discipline wasn't anything scientific so needing math wasn't in my college curriculum (switched from business to psychology then to art and advertising). I took another class, Discrete Math, from the same teacher my senior year as an elective and absolutely loved it. I never skipped a day.
He was a great teacher, and the way his class was set up for grading and not really giving a shit about homework was perfect. If I were to ever teach math later, his format would be how I would do it.
"Math professor" probably means at the college or university level -- high school math is widely regarded as complete and utter BS.
I've taken... a rather significant pile of maths classes at this point (I'm majoring in it), and I've never felt like any of the college-level maths classes assigned busywork. I may not have liked the size of the workload (oh god, real analysis), but I've never felt it was unreasonable.
I think you're interpreting "math professor" as "school teacher", while others are talking about the tenured kind of professors. "Students" here are researchers, who do work potentially ostensibly for society, not just homework for their own education.
Indeed, we hate extraneous paperwork:
http://www.mathjobs.org/jobs
and are trying to change the library system:
http://thecostofknowledge.com/
Now the intrinsic value of research math as a whole may be debated, especially that of the bottom 90% of researchers (and I would not say I'm in the top 10%).
But I have really not observed math professors to be guilty of what you claim. Quite frankly, math itself is hard enough; there's no point in setting additional hoops for students to jump through. It would just make us look foolish, and waste our own time (in addition to that of others).
I can't speak for other disciplines.