Why is Valve getting the money and not, say, Bethesda?
Like, sure, some money. Maybe 10%. Or however much they're getting from TF2 stuff. I doubt that is 75%, though.
Some of that money should go to valve, and some to the maker of the original game creator so it insensitivizes game makers to make their games workshop compatible.
But MOST of it should go to the content creator.
Also, Mods should not REQUIRE purchase. They should have the ability to be donated to.
They are mods. Not guaranteed working or even good content.