I'm not aware of anyone here who would claim that LW is one of the most important things in the world right now but I think a lot of people here would agree that improving human reasoning is important if we can have those improvements apply to lots of different people across many different fields.

There is a definite group of people here who think that SIAI is really important. If one thinks that a near Singularity is a likely event then this attitude makes some sense. It makes a lot of sense if you assign a high probability to a Singularity in the near future and also assign a high probability to the possibility that many Singularitarians either have no idea what they are doing or are dangerously wrong. I agree with you that the SIAI is not that important. In particular, I think that a Singularity is not a likely event for the foreseeable future, although I agree with the general consensus here that a large fraction of Singularity proponents are extremely wrong at multiple levels.

Keep in mind that for any organization or goal, the people you hear the most about it are the people who think that it is important. That's the same reason that a lot of the general public thinks that tokamak fusion reactors will be practical in the next fifty years: The physicists and engineers who think that are going to loudly push for funding. The ones who don't are going to generally just go and do something else. Thus, in any given setting it can be difficult to estimate the general communal attitude towards something since the strongest views will be the views that are most apparent.