God damn it you're not getting the point.
Anyone could really post anything in Steam Workshop, like in G-Mod, 1/4 of the mods there are either broken, incompatible, or just plain stupid.
Not sure how the forums are any different.
Ah, right, the Fail Bin.
hmm.
Not as if Blockland would ever really need that anyway. Installing mods is pretty straightforward I see no reason for it to use Steam Workshop anyway. Also keep in mind there are a very very small amount of games on the Steam Workshop out of the huge amounts of games on Steam.
Garry's Mod is a bad example because it's community is stuff idiots.
Blockland on Steam would probably attract a lot of the Garrys Mod crowd, I think.