He also makes quality comments, including the expression of some insights that would be punished if made by a 'human'.

Yes, but the vast majority of his comments concern his paperclip agenda. If a larger proportion of his comments were insightful rather than just funny I would be happier, but as it is his noise:quality ratio is rather high.

This is not a singularitarian website (although rationalists are often singularitarians.)

A significant part of the Sequencess is made of posts that argue for a singularity in the near future, with complete seriousness. A large number of us are not singularitarians but I don't know whether I would say the community itself isn't singularitarian.

Also note that we spend a lot of time here discussing fanfiction that is written by the lead researcher in the SIAI. We cannot credibly claim 'sensibleness' or sophistication.

We also have lots of posts about more serious topics. Having fun threads where we discuss HP and Twilight fanfiction doesn't mean that the community as a whole isn't trying to present itself at least somewhat seriously. And most top-level posts that are openly silly or non-substantive get heavily downvoted.

As an example of the somewhat serious nature of the community, there seem to be a fair number of people who have had personal epiphanies (mostly about atheism) that have had a huge impact on their life as a result of reading the Sequences.