They could have kept the HTML view as the only public view. It would benefit everyone, as it was faster than the react app. Instead they now have to keep backporting security fixes to the 3.5.x branch for admins who don't want to force the new view on their users. (Well, the 3.5.x branch will stop getting security updates in three months, we'll see how many admins will still refuse to update to 4.x.x then.)