Eh.. I can't say this isn't dumb.
The developer basically said he's gonna keep the itch version up to date with the steam version.. but he pretty much doesn't understand how steam keys works and thinks he can't give people steam keys (Or just doesn't want to go throught the problem of giving those to people.)
He also is going to increase the price on Steam because he wants his ten bucks apparently? So he's going to raise the price a 30%.
I don't know, the whole thing seems lazy and shaddy, but that's the magic about indie devs.