I doubt this will happen. As of right now, only certain types of mods can be placed in the mods folders, others need to be placed over game files to overwrite them. Also, unless the game becomes more moddable, I doubt we will see a huge amount of mods even though there are quite a few things you can mod.

Why? What is the downside?

I concur with GFirefly.  I would not use it either. 

Never was a big fan of "automatic mod updates"; another downside is when I think of games like Torchlight 2 (among others), the workshop actually stifled all modding potential by limiting how many mods you can install at a time.  Which instead of making modding an open-ended, valuable, and enjoyable experience -- into an annoying chore with far too many rules. 

I vastly prefer installing mods manually, having full control what goes into my game, updating them whenever I choose, and not be limited by silly restrictions. I'm perfectly happy solely using these forums, and perhaps on rare occasion, the nexus.

I would never have used or created a mod for Torchlight 2 had it not been so easy. I have no idea of the numbers, but as pure speculation some games that are extremely popular probably attract a mod-user population of maybe up to 50% (thinking Skyrim here). I doubt this many would use it for LH, but that is also because I suspect at some point the Steam population playing the game won't be very active, and especially during sales people sometimes barely play the games they buy at all.

The main boon from games like Skyrim and Torchlight on the workshop is that impressions are changing about modding to the idea that using mods is easy, rather than a hassle to track down and a technical chore to install like they have been forever before. So one would only expect mod populations to continue to grow, and a bustling mod community is only an attraction to the game, which users may weigh favorably in purchasing even if they never get around to using. And there are the unforseen intangibles of extending the modding community, who knows what benefits may be reaped from doing an awesome thing for hardworking volunteers?

I am not sure what the technical and security considerations are with using the Workshop. It seems like the issue of overwriting core game files can be solved by:

1. Loading the mod files in an order from a mod menu at startup

2. Ordering them in the mod folder this way

3. Using either the unaltered game file if no mod existed or the last file from the mod folder if one did

This puts stability at the mercy of modders, but people expect crashes from modded games to be the modder's fault.

I don't know what kind of security problem can occur with mods, and what kind of liability that puts Steam/Stardock with. I know the games that I have played with mods on the Workshop have all been created almost entirely with developer provided tools. I know that a lot of modding work is outside Stardock's provided tools and involves writing XML files. I know enough about security to know there is probably a danger there, but that is not my area of speciality.

I think visibility and the size of the audience adds huge incentives to modders. Modding is a showcase of ingenuity and creativity, multiplying the size of the audience through user-convenience would seem to be exactly what modders want.

I understand that is the way it works now, but there is no reason it has to work that way. It is not much work at all to pull data in the order I gave in the post above, just change the logic of where you open the data files from. Stardock would have to rewrite the code to do this, but it would be just about the easiest thing in the world they could do for modders, if some other consideration wasn't stopping them. (the mod menu I suggested would be UI, so I don't how much work that would be, but the open file logic is simple)