I really struggle with this; to this day I haven't found a good resolution. I'd say by analogy you could also say: "You don't have to pursue people romantically." It's really, really true: you don't. No one will blame you for keeping to yourself. In many settings it may even be better (example: a club, where the club organizers find the drama caused by romantic entanglements annoying). But there's a problem behind th…
If something topic is not pleasant -- walk by, and satisfy your social impulse in some other way. Go to Hacker News and leave some comments under topics you find interesting. Go to your local Reddit and discuss how badly your town services work. Find a forum for your favorite series and start a --flamewar-- heated discussion about motivations of one of the main characters. In the age of internet, the possibilities for communications are endless.
(In-person/private communications is harder, but that's not what the post was about)