1. Software patents are a huge, huge, existential crisis facing our industry.
2. So huge, in fact, that nobody wants to deal with it. We can't realistically figure out if the libraries we are using are covered by patents, and given how broken issuance is, they probably are.
3. So the only practical solution is to use MIT licensed libraries, pretend there's no patent issue, and put our heads in the sand.
4. But Facebook's BSD+Patents license made us think about patents. Nobody stopped and said "can we use Angular? Are there patents on core elements of it?". But people did stop and ask that about React, because Facebook was (accidentally) making people think about patents, and the more you think about patents the more you wish you were a plumber and not a dev so all you'd have to deal with is toilets blocked with shit, and not software patents, which are much worse.
5. Now that it's under an MIT license it's just as dangerous to use React (maybe more) but we can pretend it's safe again.
Notice that Wordpress's decision to switch from React (which probably led to this) was quite clear: They were not switching due to patent concerns about React, they were switching because the non-standard license was stirring up FUD and making people ask them uncomfortable questions. (We know this because they explicitly said so, and also because the leading contender for a new library was Preact, which is strictly more dangerous from a patent point of view than React under every possible circumstance, but has a license that lets your pretend everything is okay easier.)