How did Valve F it up? I don't think they really had a chance of really making it work because most developers (particularly the big ones with investor pressures) are averse to taking a leap of faith. Plus many have actually tried and plenty found it too daunting. Bethesda Softworks (Fallout 4) went on record saying developing on Linux was too mercurial, with no consistent target that helps to keep development on track. This sounds like an industry that, if Valve were to get too pushy, may respond by bailing out of Steam. That would be the last thing Valve would want.