I just did a search for "("Good Judgment Project" OR GJP)" and got only 87 hits, so most of your results might merely have been recent comments/posts in LW's sidebar.
Looking through the first couple of pages of hits I see
a link post for GJP season 3, and the only comments are the ones I linked in the grandparent (I upvoted them anyway because they're interesting feedback)
a link post about an earlier GJP round, which does actually have a lot of GJP talk among its 55 comments
this Gunnar_Zarncke post
part 1 of Morendil's 2012 "Raising the forecasting waterline", about participating in the GJP, which has 108 comments but most aren't about the GJP
a short follow-up by gwern to post 2, with 2 comments
part 2 of Morendil's "Raising the forecasting waterline" (and 22 comments)
your user page, which comes up because of the parent comment
a link post to an FT article on forecasting, with comments that don't talk about the GJP
the list of recent comments for LW's Discussion section, which comes up because of the parent comment
VipulNaik's "Some historical evaluations of forecasting", which discusses the GJP for a paragraph (the only comment doesn't mention the GJP)
the list of Discussion posts tagged "tetlock", which matches because post 8 comes up
Morendil starting a short subthread about the GJP under "The Martial Art of Rationality"
post 5 at a different URL
an unrelated post which only comes up because Google indexed it while my GJP-mentioning comment was in the sidebar
another VipulNaik post which again discusses the GJP for a paragraph; all 3 comments talk about something else
Morendil's "Raising the waterline" mentions the GJP a few times (none of its comments do)
VipulNaik's "An overview of forecasting for politics, conflict, and political violence" lists various forecasting efforts, and discusses the GJP as one of them across several bullet points (0 comments)
VipulNaik's list of submitted posts
Morendil mentioning the GJP in a one-sentence comment.
VipulNaik again giving the GJP a paragraph in "Domains of forecasting" (none of the 4 comments mention the GJP)
That is more commentary than I remembered (I'd definitely forgotten about Morendil's 3 top-level posts), and yeah, "little interest" is too strong. I'll change that to "sporadic discussion", which I think is fair. Aside from Morendil's posts and this G_Z post, most of the mentions of GJP on LW seem to be asides or links to external articles, and they're spread out over about 4 years.
Follow-Up to Good Judgment Project, Season Three.
During the last forecasting season I took part in the Good Judgment Project (GJP; see also the blog) and this is a short summary of my participation (actually triggered by hamnox comment).
The GJP estimates world events like
To participate in that study one has to register (can't remember where exactly I stumbled over the link, possibly the one at the top). And one has to do an preparatory online course and one has to pass an online test. At least I had to complete it. Whether the result affected my assignment to any group I can't say. The course explains the scoring and gives recommendations for making good forecasts (choose forecasts one has an edge in, estimate early, update often, do post-mortems). The test seems to test for calibration and accuracy by asking for known (mostly political) events and whether one is sure about them.
The current forecasting season started in November 2014 and has just ended. I invested significantly less then half an hour a week on 8 questions of about 100 (and thus less than I projected in an early questionaire). I did 2 to 15 updates for these questions and I earned a score in the middle range (mostly due to getting hit by an unexpected terrorist attack). As I just learned I was assigned to the study condition were I could neither see the total group estimate nor the estimates of the other group members - only their comments. I was somewhat disappointed by this as I had hoped to learn something from how the scores developed. Too bad I wasn't in a prediction marked group. But I hope to get the study results later.
I will not take part in further rounds as I shy the effort for the types of forecasts which are mostly political. They are political because the sponsor (guess who) is interested mostly in political events - less in economical, environmental, scientific or other types. But I enjoyed forecasting artic ice cap melting and ebola - and netted a better than average score on that.
The scoring - at least in this group - is interesting and uses an averaged Brier Score - averaged over a) all forecast questiontion and b) within a question over all the days for which a forecast is provided. I intended to game that by betting on questions that a) I could forecast well and b) that had an expected reliable outcome. Sadly there were few of type a.
From this experience I learned that