Because I don't want my default view to be "triage." If GitHub allowed default issue views (and reflected that in the issue count in the tabs as well), then maybe. But currently, it doesn't work. I've tried it at large project scale across many (multiple projects with more than 20K stars and millions of downloads).
Compared to that, this system has been a huge success. It has its own problems, but it's directionally better.
Compared to that, this system has been a huge success. It has its own problems, but it's directionally better.