Sure, if we were in an alternative reality, things would be different.

Valve built a platform that gamers like, and gamers like it for all the choices Valve made.

I also find it interesting you chose "not allowing reselling" as a thing that would have made users not like steam... but not allowing reselling is probably the feature that game developers like the most! I wouldn't be surprised if developers would choose to keep the 30% fee over dropping the fee but changing to allow reselling.