My take is that the goal is to give more useful advice than what people are currently getting. For example, giving science-based advice on relationships as I do in this article is more useful than simple experience-based advice, which is what the vast majority of articles on self-improvement do. If it is better than why not do it?

Remember, the primary goal of Intentional Insights is not to market rationality per se, but raise the sanity waterline as such. Promoting rationality comes only after people's "level of sanity" has been raised sufficiently to engage with things like Less Wrong and CFAR. More in my comment on this topic.