With a popular open source project, you'll quickly get to a number of bug reports that you have no chance of ever solving. You will have to focus on the worst ones and ones affecting most users.
At the same time, you want to communicate to users that this is the case so they don't have wrong expectation. But also, psychologically it is demotivating to have a 1000+ open bugs queue with no capacity to re-triage and only two maintainers able to out a few fours in every month or every week.
In open source, "won't fix" means either "not in scope — feel free to fork" or "no capacity ever expected — feel free to provide a fix".
The optimization problem is how do you get the most out of very limited time from very few people, and having 1000+ open bugs that nobody can keep in their head or look for duplicates in is mentally draining and stops the devs from fixing even the top 3 bugs users do face.
