I'm even fine with this (I hate software patents).
But it seems very wrong to essentially be able to take what you want from small companies because they are afraid to take you on.
Regardless of what mechanism you use to achieve it.
"and they are likely saving Facebook a whole host of headaches."
I am empathetic, but i also disbelieve this. I'm aware of every headache Google has ever had in these situations, and i can't imagine Facebook's are particularly different.
I can state affirmatively that this license would not have prevented even one of those headaches. Thus it would have been infinitely more helpful if they had cited any examples.
As for your viewpoint on the scenario. FWIW: yes, i am certainly biased by what i've done. But I actually have dealt with a tremendous number of startups, from both sides of the fence (I also do due diligence on this side, and have helped plenty on the other side). The number who would have no effective recourse under this license, who would have had effective recourse before, is quite high.
Would that recourse only come into play when they are essentially fcked anyway? Yeah, maybe. But it's worth something*.