The same thing could have been said about Github three years ago. We use Upverter at Lockitron for one off's (factory test boards, misc. for fun hack boards for our coffee machine, etc.) The tools aren't there today for mass production stuff (more of a problem with the vendors than Upverter). I would be surprised if this is always the case.

As Upverter grows, so will their applicable use cases. Online services have this weird power-law thing going for them that software from a single vendor can't keep up with on 5 year timescales.

Git fully works without Github.

Can't even view your schematics if you stop paying every month to Upverter or they close.

We totally understand that fear. This is our approach to solving it: https://github.com/upverter/schematic-file-converter