Also, making something suitable for humans means having lots of empty space where the human can walk around (or float around, rather, since we're talking about space).
I agree that it may be best to avoid needing the space and facilities for a human being in the satellite. Fire and forget. Launch it further into space instead of back to earth for a decommission. People can salvage the materials later.
This effect can be somehow overcome by exercising while in space but it's not perfect even with the insane amount of medical monitoring the guys up there receive.
It's theoretically possible for sure, but we've never done that in practice and it's far from trivial.
Are there any unique use-cases waiting to be unleashed?
Keep in mind economics is all about allocation of scarce resources with alternative uses.