I'm pretty sure that Valve made quite the pretty penny off of just user made maps alone for CS Source?
"Dude check out this crazy game, you can SURF around, kill people, and level up your character for crazy new powers" was the reason I bought CS Source after seeing it at a friends house...
Back in your day, ID etc weren't profiting off of the mods you made. They were shared freely in other fan spaces.
Apples, oranges.