I'm not a stranger (😉) to buying games I like for different systems/providers, and most of those cost a good bit more than both releases of "That's Not My Neighbor" combined!
I never expected a refund for the itch.io game, or a steam key for the Steam version, even though that's a sweet thing to have tried to make happen for the players on itch.io, it's totally reasonable and understandable why you couldn't make that happen. I remember reading about how stressed you were when the Steam version release came out because Steam only allowed a very limited number of keys to be given out, if at all.
I'm glad the game has blown up in popularity, and your success is exciting especially for those of us that want to see you create more things that you want, but even still you won't be able to please everyone, there would always be people that are mad about your decisions, so just try to make decisions that you feel good about and try to ignore the negativity. <3