It's not entirely wrong. If you get into a patent dispute with them, you lose the patent grant to React, which means if they have any (none have been seen yet) patents related to React, they can very quickly countersue you, making the patent suit from your end, while still valid, a guaranteed financial ruin for any business not on their scale. We're not saying the license + patents combination explicitly grants Facebook the right to infringe on your patents, but rather it's a trap clause that makes it impossible to survive a patent lawsuit against them by virtue of using React, which in _effect_ is like a patent grant back to them.
