Defense and deafness
"... that they think is a valuable part of their defensive portfolio because of its broad applicability."
So they're lots of people all angsty because of the patents clause. And they each would swear they would never be party to suing Facebook, so why the "hostile action" by Facebook?
And then their company gets taken over by someone. And then another takeover. And a few steps later they find out their 'feelings' don't mean nothing, and there's a someone looking only at what their technology is worth in patentable ideas. You don't even count as cannon-fodder at that point, but your work could be used offensively in a patent war.
Now how do you prevent this being possible? Because Facebook apparently is looking at the world as being a bit more, well, angsty, than you do.
BTW: This obviously does not apply to that open source where a company is not declaring ownership of a product. If it can be or has been turned over to a community governance or whatever, then there is no one - no company - who would be suing Facebook, right? So I'm really rather confused at these pure open source projects getting confused at this. Or can you tell me who would be suing Facebook and get into this problem. A 'foundation'?