Well, considering most of my rules have devices in them...If you were to wipe away all my devices I'd pretty much be recreating all my rules anyways to fix the now defunct devices. And for those of us with lots of rules that might not remember what all was in them...yeah...you would not only be reconnecting everything AGAIN but you would be creating rules again. Heck at that point you'd be better off with a printout of of the screen and just start from scratch. That would be about the worst upgrade path ever.
However. I don't think the Hubitat team is that stupid. I'd be shocked if the existing USB stick will not work with the new hub and it's not a simple backup/restore procedure to upgrade.
Plus, if you put a user in a position like that to start over...it just opens the door for them to use another product since they are starting over anyways. That's a bad business decision and terrible marketing. Makes way more sense to bring someone into your platform and keep them there. Or make it really hard for them to leave (starting over).