What's the point of just showering these things with bug reports when the same tool (or a similar one) can also apparently fix the problem too?
Imagine you're a humble volunteer OSS developer. If a security researcher finds a bug in your code they're going to make up a cute name for it, start a website with a logo, Google is going to give them a million dollar bounty, they're going to go to Defcon and get a prize and I assume go to some kind of secret security people orgy where everyone is dressed like they're in The Matrix.
Nobody is going to do any of this for you when you fix it.
Doesn't really fit with your narrative of security researchers as shameless glory hounds, does it?
Note FFmpeg and cURL have already had maintainers quit from burnout from too much attention from security researchers.
I don't know if you'd be satisfied with that, but certainly this would allow them to easily make the blog posts you seem to be complaining about, all while making the load on maintainers rather minimal, at least insofar as blog posts appear to be quite infrequent compared to the total amount of vulnerabilities they report - around 20 vulnerability reports per year certainly seems like a manageable load for the entire FOSS community to bear, especially given almost none of these 20 yearly vulnerability reports would go to ffmpeg (if not literally none, given the Project Zero blog has 0 search results for "ffmpeg" or "libav"), and a significant portion of their blog posts aren't even about FOSS at all but instead about proprietary software like the operating systems Microsoft and Apple make.
I do think such a thing would be bad for everyone, though (including the ffmpeg developers themselves, to be honest) - Project Zero is good for everyone's security, in my opinion, and even if all FOSS developers were to universally decide to reject all Project Zero reports that don't come with a patch, and Google decided to still not make such patches, people being able to know that these vulnerabilities exist is still a good thing nonetheless - certainly much better than more vulnerabilities being left in for malicious actors to discover and use in zero-day attacks.