Have you actually read "The end of History"?
The Hacker News guidelines page[0] is a pretty incredible document. One of the smallest but most central insights in it is "Please don't comment on whether someone read an article. 'Did you even read the article? It mentions that' can be shortened to "The article mentions that."
Unlike most sites, HN is very intentional about optimizing everything in the site for quality of discussion, not for outrage and conflict and dismissal. Everything about how the Karma system works here and the way audiences react to posts differently here than on Reddit ties back to that goal (HN isn't interested in page views or ad revenues, it wants to be interesting to smart people so they stick around and participate).
Again, following the advice in the HN guidelines I will "assume the best interpretation" of your comment and say yes, I and others are quite comfortable generalizing from a specific quote that happens to mention how to respond to comments about a post to understand how that recommendation would apply to comments about other articles and topics without needing that to be explicitly spelled out, and yes I've read quite a number of works by Fukuyama though in my opinion "The end of history" is far from his best work. I've personally found "The origins of political order" to be much more thought provoking.
Nonetheless, the book's thesis is hard to reckon with:
> What we may be witnessing is not just the end of the Cold War, or the passing of a particular period of post-war history, but the end of history as such … That is, the end point of mankind's ideological evolution and the universalization of Western liberal democracy as the final form of human government.
And it is always possible that Putin himself has not read (or, like so many of us, merely misunderstood) Fukuyama's work as well.