As an outsider (not an oss maintainer, but a contributor), the decline to merge imo was understandable - the maintainer had a strategy and it didn’t fit. They gave reasons why - really nicely - and even made a call to action for PRs placing architecture docs elsewhere. Your response tonally was disparaging, and the subsequent pile on was anti productive. All due respect to your experience as a maintainer; in that role, can you imagine seeing a contribution that you are not interested in, and declining/forgetting to or being too busy to engage, imagining that it might get dropped or made better while you are busy with your priorities?
Putting myself in your shoes, I can see why you might be annoying at being ignored. Suggests this change is really important to you, and so my question would be why didn’t you follow the maintainers advice and add architecture docs?
Those rejected README changes only served to provide greater transparency to would-be users, and here we are a year and a half later with woefully inadequate movement on that front.
I am very glad folks are working on alternatives.