To answer the one who wrote first, I have some things to say, because your questions do not seem many to me! It seems more like a reflection on a critical trend of Itch.IO. Have you ever wondered why, when you put an executable demo, you get several downloads, while if you sell a game for a fee, everyone is reluctant to buy it (except the first copy)? One possibility could be that those who download the demo re-use your data and software on their own or with others. A second possibility is that the ideas and prototypes made by you, are reused by advanced software houses because are more interesting anc can they be re-developeds..
Also I have seen beautiful games, but few criticisms ... What would it mean to talk too much? Advertise a competitor. All on this site or almost, are single brilliant programmers or advanced software houses...