The important point is, you don't lose FB's license grant if you counter sue them. You lose the grant only if you initiate a lawsuit.
Here is the relevant section from the PATENTS file:
if Facebook or any of its subsidiaries or corporate affiliates files a lawsuit alleging patent infringement against you in the first instance, and you respond by filing a patent infringement counterclaim in that lawsuit against that party that is unrelated to the Software, the license granted hereunder will not terminated under section (i) of this paragraph due to such counterclaim.
It is an opinion held by many (many here) that Software Patents bring no value to the community and need to be abolished. I agree with them, and hence I disagree with you. I did not down vote you.
I guess it's possible to replace react with preactjs.com with a little amount of effort.. In cases where the legal aspect prevents you from suing FB..
Not true any more:
https://mobile.twitter.com/paul_irish/status/754864479460929...
That patent license they have in their project basically means you can only use React as dev in a company if your company does not have patents or noteworthy IP.