How do you think they got to where they are? by not believing and not working hard? Valve has been working at what they do for longer than some people commenting here have been alive. Steam has been around for 19 years.

Do you believe developers should be able to use something a company has spent the last 19 years investing in and building... for free or cheap? Is there a competitor in the market that would bring them as much exposure while not charging as much? The only thing I can think of are platforms like EGS, where they basically pay people to sell their games on there, so they can grow the platform.

I haven't done the math myself, but I'm guessing indie developers would be hard pressed to make the same money without using Steam as they do using Steam, even with the "fleecing" you're talking about.