I agree that it improved dramatically, but only because the starting point was so low.

The starting point is always low. Your criticism applies to me, a mainstream, applied mathematics graduate student.

• I started research in my area around 2009.
• I have two accepted papers, both of which are relatively technical but otherwise minor results.

I also wasn't working on two massive popularization projects, obtaining funding, courting researchers (well, I flirted a little bit) and so on.

Applied math is widely regarded as having a low barrier to publication, with acceptable peer-review times in the six to eighteen month range. (Anecdote: My first paper took nine months from draft to publication; my second took seven months so far and isn't in print yet. My academic brother's main publication took twenty months.) I think it's reasonable to consider this a lower bound on publications in game theory, decision theory, and mathematical logic.

Considering this, even if MIRI had sought to publish some of their technical writings in independent journals, we probably wouldn't know if most of them had been either accepted or rejected by now. If things don't change in five years, then I'll concede that their research program hasn't been particularly effective.