It still lowers the value of IP patents, since that value has most often manifest itself in suing Facebook/Apple etc.
With their value being even marginally reduced, maybe some patents will never be filed, or the value proposition of setting up patent-litigation entities is reduced enough to discourage it.
Basically this is net-positive for anyone who doesn't own or plan to own patents, even if it is even better for Facebook.
Patent litigation against such companies is often carried out by specialized entities, so those have nothing to lose by having their "React" patents revoked.
With their value being even marginally reduced, maybe some patents will never be filed, or the value proposition of setting up patent-litigation entities is reduced enough to discourage it.
Basically this is net-positive for anyone who doesn't own or plan to own patents, even if it is even better for Facebook.