Piggy backing off this comment.

My concern is with the idea that there isn't any quality assurance. With game development companies, it's almost okay to not curate what goes on Steam because we know who those companies are. We know who works there. We can decide to not buy from such companies or individuals if they rip us off. With mods, this isn't possible. The modders are protected through anonymity. If a modder decides to upload a mod and not support it, it doesn't matter if it breaks. There is absolutely nothing we, as the consumers, can do to get a refund (past 24 hours) or hold the modder accountable for a faulty product. We can avoid that steam name, but then the modder can create another Steam account.

Also, the refund policy just isn't good enough. It could take 24 play time hours to even access the content in a mod to see if it all works. Mods which add quest lines come to mind. Short of me using console commands to immediately check that the quest line functions, what am I supposed to do? Should consumers have to access the console command to make sure that the product they bought is useable? What about individuals who intentionally break their mods? What are you going to do to protect the unknowing consumers from getting burned?

And how are you going to address stolen content? Some modders have decided to stop modding because they fear that their work will be downloaded from nexus mods and uploaded onto the steam workshop for profit. Now, the curation system should prevent the stealing of entire mods, but what about parts? There are mod packs which add multiple weapons to Skyrim. How are you going to prevent a malicious individual from ripping one weapon from the pack and selling it? I suppose modders could attempt to submit DMCA claims, but I wonder if that's even possible. Obviously, we haven't really set a legal precedent for this kind of thing and the copyright for this content belongs to Bethesda. What recourse does a modder have to not have their work stolen and profited off of?

Also, and this could be my misunderstanding, but do you need to own the game on Steam to be able to add content to the Steam Workshop? A solution for a modder who doesn't want their work stolen would be to upload their mod to the Steam workshop themselves, thereby preventing anyone else from doing so. Now, if you need to own the game on Steam to upload to the Workshop, you're preventing a modder from protecting their work unless they purchase the game through your service. That is unacceptable.

I could see all this as a reason for many modders to stop modding permanently. What will the paid workshop be then? Instead of being a place to reward skillful modders, it will be a place full of people trying to exploit consumers for a quick buck. All you need to do is look at the app store and see how full of garbage it is. Most of what is on there is freemium games which require people to invest thousands of dollars to play. And what good free games are uploaded end up being cloned and uploaded by someone else. I think you need to seriously evaluate the impact on your store this will have. If you aren't going to take action to protect modder content, you need to let this idea go. Your bottom line isn't worth the amount of damage this does to pc gaming.