As a maintainer, I never found it particularly useful. Open source projects aren't generally democracies, and clicking an 'upvote' button is so low-effort that it wasn't really a good signal anyway.
My experience with it on trac and uservoice is that it's an easy way to filter out things that exactly one person cares about, and not much more. The main benefit is that it reduces the number of spammy +1 comments you get.
@steveklabnik (since hn won't let us nest further): why not just hit the subscribe button on the right?
> (since hn won't let us nest further)
ProTip(tm): HN does this when you try to reply too fast. You can click 'link' to get around it, though. :)
I never saw that! Thanks. Somehow that just escaped my vision.
I do wish it was easier to subscribe to a particular issue without having to leave a sole :+1: comment.