Making a paid mod system work for Skyrim and Fallout 4 wasn't going to be easy. Bethesda has apparently called for someone to hold their beer while they put some paid mod files on players hard drives, whether they purchased/unlocked them or not.
Implementing Bethesda's paid mod Creation Club system was going to be a delicate matter even under the best of circumstances. It now appears that the company was a little ham fisted with how they plan to get paid content onto players hard drives.
The problem here is that very few players have unlimited disc space at their disposal, and a lot of those players have a download cap in place with their ISP.
Forum user BlueBeer quite accurately summarised why this is a bad idea, "You just used MY bandwidth, and MY system and storage for something you are trying to SELL me. All without asking/telling me."
Bethesda has responded by adding the feature to their Known Issues List for Creation Club, but at this point it is relatively safe to assume that by "Known Issues" Bethesda means that they knew exactly what they were doing even before the consumer backlash got rolling. And they would have gotten away with it too, if it weren't for those modding kids.