NFS on a well designed and maintained LAN is ok, but on any network less reliable I agree it's the wrong abstraction. You can only get away with hiding the network in those rare situations where the network can be made that robust.
I worked for the last ten years at a major animation studio where we pushed huge I/O over NFS every day. This was a lot easier to do with NFS semantics than it would have been with a less "fallacious" model, but we only got away with it because we had complete control over the whole network.
