That being said, I'm not in favor of transferring maintenance work to the community for this set of hooks any more than I am for something on the parsing side. In general, I'm in favor of as much extensibility as we can reasonably create, but with a complicated proposal like this one, the community should expect to be able to get something out of it. And so far what I hear Jan saying is that these hooks could in theory be used for things other than Amazon's proprietary efforts and those things could in theory bring benefits to the community, but there are no actual plans to do anything with this that would benefit anyone other than Amazon. Which seems to bring us right back to expecting the community to maintain things for the benefit of third-party forks.
I'm quite sure I said I'd open source my MySQL implementation, which allows Postgres to appear to MySQL clients as a MySQL/MariaDB server. This is neither proprietary nor Amazon-related and makes Postgres substantially more useful for a large number of applications.
As Jan said in his last email, they're not proposing all the different aspects needed. In fact, nothing has actually been proposed yet. This is an entirely philosophical debate. I don't even know what's being proposed at this point - I just know it *could* be useful. Let's just wait and see what is actually proposed before shooting it down, yes?