Frankly I think the amount being award by these companies is minuscule when you compare it to the amount of damage this information could have caused Facebook in the wrong hands.
Also, I can personally live for a year on that kind of money. But that's another issue.
On the other hand, that is maybe what they would have payed for a real audit of a few days/weeks and it's not even sure the vulnerability would have been found (especially considering the size of Facebook). So yeah maybe they also deserve more.
I'm mixed.