The http://www.bethblog.com/2015/04/27/why-were-trying-paid-skyrim-mods-on-steam/ said less than 1% of Skyrim audience, so it could be anything up to 1% of total sales on all platforms or total sales on PC.
Nexus http://www.nexusmods.com/skyrim/about/stats/? that it has 17 418 "members with files" in the Skyrim section. Given your number that Steam Workshop has ~24 000 mods, and a lot of those also exist on nexus, the two sites are unlikely to have much more than 25 000 mod authors between them. Given that there are other communities out there that do not frequent nexus or SW, e.g. the German and Japanese modding communities, the actual number of mod authors with a publicly published mod could be ... maybe twice that?
Or maybe they did not know? It was pure coincidence that I visited nexus the Saturday after the announcement. The first I heard of it in my usual venue was on the 28th where slashdot ran the story that Valve had pulled the plug. I could easily have missed that story as well.
There are also a lot of lurkers who do not comment for a multitude of reasons. Maybe they feel that someone else expressed their point of view, so they don't see the point in writing a comment, maybe they felt they could not contribute anything, or simply because they were shy.
The point: The people who did not comment, could have done so for all sorts of reasons, and we should not be putting words into their mouths, because we really have no way of knowing how they feel.