If the issue is not delegating etc then that's one thing, but there's also the scenario where others don't want to step up and take any responsibility on a project. Or if they do it's not for the Malcolm-reasons https://news.ycombinator.com/item?id=5402137 but for the ego trip of being part of a popular project. Yep, been there and burned by it, so just a little cynical...
Then again, I have never been in a project that got 75 new pull requests per day...
My interpretation of it is that he is lamenting how the issues list has become a catch-all for everything from bug fixes (which are fine) to random non-Backbone related development questions, and looking at the issues at lot of them are in the form of "HALP!" with a very light description.
Let someone else close issues that are offtopic or a bad idea. He insists that this means that 'you have more people who have to read everything' but it absolutely does not. It means you need to learn to trust that if so-and-so closed it, it should be closed.
Because no one else cares. It's a huge problem in Open Source projects. Most of them are single-person projects. One person does the coding, bug fixes, releases, documentation, and answering questions on the list.
For the OP on github, he needs to learn triage. There is no reason to be polite to people who can't be bothered to read the documentation. My mantra is "if you don't care enough to put some effort into it, then I don't care, either. Go fix it yourself."
He needs to quickly read issues, and close the idiotic ones with minimal comment. If they keep arguing, block them.
A good project maintainer can't afford to waste his time on loud-mouthed idiots. There are too many quietly competent people who need his time.