Earlier quoted context omitted.
If Facebook has a patent on React, it's almost certainly going to be on the vdom concept. If Facebook has a patent on the vdom, then all the projects in your list violate the patent, and none of them come with even a conditional patent grant from Facebook. If Facebook does not have a patent on the vdom or other React technology, then those other projects are safe, but so is React , since termination of the patent gra…
Being sued, whether the patent is valid or not, is really expensive. Unless you're Google, or of similar size, you're going to lose just due to the costs. Using React just opens you up to liability, with no real benefit (other than using React). Why would you use it?
How?
Again, if they have a patent, they can sue you if you use one of the alternatives mentioned. If they don't have a patent, they can't sue you if you use React.
What's your thinking behind saying using React adds liability? Because to me, it looks like either it does nothing or it reduces liability.