I see requests for this a lot. Is there a reason not to just do this at the OS level, with FUSE (sshfs) or GVFS or something - then it'll just work everywhere?

I see requests for this a lot. Is there a reason not to just do this at the OS level, with FUSE (sshfs) or GVFS or something - then it'll just work everywhere? I can't see why every editor should be implementing filesystem stuff?