2 hour return policy can already be a problem for a very short indie game. There was one which you could beat in 2 hours and refund and people did that.

GOG gets away with their policy because only people who believe in GOG ideallogy go there, and they won't refund a good game. If steam did that, abuse would skyrocket.

And in my country, unless explicitly stated otherwise, most physical goods can't be returned if they are used.