Am I the only one who doesn't really feel that 30% is that ridiculous of a cut? Typical markups for retail are at least 50%. While steam doesn't have physical storefronts or retail staff, they do actually provide a lot of value with their software. Now other launchers I think we can argue aren't earning their 30% cut, but steam provides numerous useful APIs, community forums, mod hosting, built in social and multiplayer features above and beyond the simple distribution and payment processing required by a digital storefront.

My issue with unity's pricing is that it's cost a) isn't tied to how it's used and b) is unbounded. Let's take a game like terraria for example. If they had used unity to build it, terraria would now suddenly be on the hook for new charges related to their game. I would at most expect unity to charge for new versions of their software as they were used in development. If my game was completed years ago, why would I continue to owe them money for a completed transaction? Secondly, terraria is the sort of game where users might frequently uninstall and reinstall as new updates come out. I'm now disincentivized to make new updates (especially free updates) that might cause my users to reinstall my game and end up costing me more money.