So many organizations do legally questionable things and mouth gag you from doing the right thing and reporting their scammy behaviour because somewhere down the line you want to make sure that when the next organization calls for a reference they don't destroy your job prospects.
A simple example related to this point is that this is precisely why it took a whistleblower to expose the shit that Facebook is doing.
If all the previous researchers felt like they could walk away and get a new job, while highlighting their great work AND calling out Facebook for what it does they would have.
I just saw an example of a sequoia funded startup firing someone during mat leave and then having the audacity to propose a onesided non disparagement clause. The person in question was close to accepting it, because she feared a potential backlash in her future career.
It's completely insane that in most societies corporations can abuse employees to the extent that they are and then employees bend over and accept it, because they might have a bad reference. Usually the only way to actually free yourself from those companies is litigation with mutual non-disparagement. That really shouldn't be the case.