Plenty of people complain vocally if you don't release your game on Steam, same deal when a musician doesn't release their music on Spotify.
I think a lot of developers will be surprised how many customers actually side with the convenience of the platform over the actual person creating the value.
Steam value to customer is huge - and it's understandable why people just go to Steam and "don't have to think about it" even when you can get the same item elsewhere, perhaps even cheaper.
I think a lot of developers will be surprised how many customers actually side with the convenience of the platform over the actual person creating the value.