When someone proposes what we should do, where by we he implicitly refers to a large group of people he has no real influence over

I'm not sure whether that's true. Government officials who are tasked with researching future trend might right the article. Just because you yourself have no influence on politics doesn't mean that the same is true for everyone who reads the article.

Even if you think that at the moment nobody with policial power reads LessWrong, it's valuable to signal status. If you want to convince a billionaire to fund your project it might be be benefitial to speak about options that require a high amount of resources to pull off.