First off, how is the industry standard proof that Valve is greedy?
Valve allows the creation of free Steam keys. That means you can literally sell it with 0% of the cut elsewhere if you choose. Valve doesn't make a cent of Retail copies or games sold on other storefronts, including the publishers.
Valve actually offers a ton for that percentage. We're talking viability, cloud saves, native controller support for everything under the sun, family sharing, guides, mod workshop, reviews, forums, and now even free linux support.
Whatever. Down with Evil Valve.