Thanks for bringing up a point to continue the conversation, unfortunate you're getting downvoted with only sarcastic disagreement to go on. I disagree, but only on a point of nuance -- ideally that financial incentive improves the quality of mod offerings, and in some cases it does (I'll take your word on Assetto Corsa mods). But I'd say it's still a net-negative on the whole because then the financial incentive becomes the goal, not a quality mod. It also gives the parent company control over visibility, so they'll promote the mods that get them the biggest cut, which inevitably will be the shiniest ones and not necessarily the ones that actually improve the game, then passionate creators get disheartened and leave.

All conjecture -- I'm not super active in any modding scene, my only experience is hitting the 256 mod limit in Skyrim a long time ago.