A dead NFS server can also stall a local desktop. This was a huge issue at Google, where homedirs are mounted on NFS. Turns out almost all window managers need frequent access to dotfiles or they will freeze. This is stupid.
Sure, but it can at least timeout, reutrn EIO, seamlessly reconnect when the connection is reestablished and few other remedies (you can't really do anything else, if this happens), something that I've never managed to make sshfs do properly.
A lot of window managers don't really deal with NFS timeouts/errors very well. One solution is something like AFS, but that comes with a whole host of issues.