Here's the reality... its a scam in favor of Facebook.
Lets cut to the chase.
The BSD License + Patents says that if you use this code, then you lose the right to use the code if you ever sue Facebook for Patent infringement.
This is a trojan horse. Facebook wants to push this code out to everyone so that it becomes a key critical component in their ecosystem. At that point, Facebook could ignore any and all software patents because if you sue them, you lose the ability to use any code that they may have donated to Open Source which you now rely on. Even if you don't directly use the code in your products, if you purchased a product that uses their code, you could potentially lose the ability to use that product.
Corporate companies love Apache licenses because it allows them to re-license the code or do pretty much whatever they want with the code free from any major restrictions.