The 30% cut is standard, and was so at retail even before Steam existed IIRC.

And the cut can't be lower?

The rush to defend Valve's monopoly is so weird since HN usually hates fat cat billionaires. Valve is raking in so much money as a middleman that Gabe Newell has ~$1 billion worth of yachts alone, in addition to the rest of his wealth, yet gamers want Valve to keep on bleeding them and game studios?