We do this because, regardless of the politics and ideology you favor, it poisons the site for its intended use, which is the gratification of intellectual curiosity (https://news.ycombinator.com/newsguidelines.html). One is about flamewars and smiting enemies, the other is about thoughtful conversation. Can't do both at the same time.
If you think politics is not the realm of intellectual curiosity and that there's nothing political about this article you're a fucking sickening human being.
While yes, there probably is a political leaning to most things one reads... There is a time and place to promote such a discussion, especially when dealing with obituaries.. Perhaps this isn't either the time nor the place.