Just because someone doesn't make games, doesn't mean they can't have an opinion on them. This is a bit of a silly take, well meaning though it is.
Let's not be dishonest, you literally went "try and make a game and see how hard it is" and "game dev is time-consuming and hard" which is true, but you're using that as an argument against people complaining (having an opinion) on the handling of the itch.io version vs the steam version. People are allowed to express frustration without needing to experience the woes of game dev first hand.