if you have a high ratio of open issues, your project looks "worse" than some other project which has a lower ratio.
Really true, but I link it back to "real bugs, unconfirmed bugs, feature requests and backlog items being into a single list".
When evaluating a project, I indeed want to confirm that there's no important bug, but I don't care about 100 pending feature requests for edge cases. Bugzilla, Trac, Youtrack... all come with default "severity" fields, GH issues do not.
But indeed, perception of projects has been completely warped, including idiots opening "is this project dead" issues because a project had no commits for a few months. A project can be complete and done, with only security fixes.