While you still may not have an edge, this still seems much more reasonable to me than most terms.
For example:
I deposit 100, play
vp, hit deuces, cashout.
else
claim $100 bonus w/ $2000 playthrough.
If I play a game with greater than .95 expectation, statistically, I still go home with something in my pocket.
Even if you are forced to play slots, it still doesn't sound bad to be given $100 for slot play after losing $100. Sure, its going to be hard to hit playthrough, but as slotchick says, you might hit the big one, which is a better chance than you had after you lost without the bonus.