You missed this part at the end of my post:

  Sure, it's definitely not slavery, but it sure seems
  highly exploitative

Also:

  The salaryman can quit. A slave couldn't.

If the problem is endemic to the culture, then quitting one job just to take another offers no real change in situation.

To run with the slave analogy, it would be like a slave being able to choose their master, but all masters beat/rape their slaves.