Why is this so hard to understand? 

 A loss rebate is basically a free roll. 
  
Let's say a $500 loss rebate.  You play 
aggressively with your own money, trying to hit whatever Target you have chosen...something substantial, a substantial win.  
If you fail to do so and lose the $500, you get the rebate in free play, which you then play through conservatively.  Even if you play a 'bad' video poker game with say 98% payback, that $500 free play (rebate) is worth expected value of $490.  You may not return exactly $490 of course.  Maybe you get unlucky and return $450, maybe you hit a couple small jackpots and return $550.  Doesn't matter, the expected value is $490. 
So you go into the rebate with chance to win big (whatever your target is) vs a loss expectation of $10.  Who wouldn't take that all day long, every day!  

  Nobody is 
trying to cash in on the rebate.  The rebate is simply the insurance policy.  I just don't get why there is even a discussion about this? 
And if your argument is that the player won't stop once he/she plays the free play through once, and will lose it all.....then you are exactly the type of schmuck the casino is looking for.