It matters in a positive sense; it's a thing that enables you to make some predictions about the state of the world tomorrow. It does not matter in a normative sense; OSS maintainer burnout is strictly a less important concern than software security, which is an externality of software development.
> OSS maintainer burnout is strictly a less important concern than software security,
Burnout means that no more fixes come - ever - and that things sit vulnerable until everyone relying on that tool takes the time to build and switch to a replacement.
Maintainer burnout is perhaps the single biggest threat to the ecosystem right now.
Stated differently -- the way OSS software is currently maintained and users are conditioned to behave, there is a capacity problem if the rate of discovery surges too sharply.
And if the capacity is overshot (which I believe is happening as we speak), users end up in extended states of being insecure.
I'm also one of the unwashed rabble who believes there is a large practical difference between a vulnerability that exists but isn't found and one that is widely known and exploitable.