I prefer having a 2nd wired connection as my backup. The satellite connection has some clear benefits, but it's still going to outer space. A DOCSIS failover won't suffer from rain fade or a something landing on the antenna.

If I've got a situation so bad it takes out both of my connections I've probably got bigger things to deal with than internet access.

The buried fiber getting cut by is really the only thing that kills the connection. Fiber can go for a long time without power from the local grid infrastructure. My cable provider has a mostly orthogonal failure mode (goes down like clockwork with the grid).