This only addresses one kind of partition. What if your servers can't talk to each other, but clients can? What if clients can't connect to any of your server

This only addresses one kind of partition. What if your servers can't talk to each other, but clients can? What if clients can't connect to any of your servers? What if there are multiple partitons, and none of them have a quorum? Also, changing the routing isn't instantaneous, so you will have some period of unavailability between when the partition happens, and when the client is redirected to the partition with the quorum.