You don’t get it. Sorry, this is an “is-ought” thing. Sure we could mandate this. But are we going to? Do the systems exist that would actually mandate this?
Looking at things right now? I would say no. We will see, maybe in up my own ass on this, but I see a pretty big set of changes coming down the pike. Adapt or die (as unpalatable as that may seem).
If you don't mandate anything, then they're going to build the dirty one.
So what kind of laws would lead to the orbital option being preferred over the ground-based clean option?