My Favorite response (from Martijn Verburg): "...could you guys work with the community to teach them to submit better proposals/patches? Many open source projects are able to do this from the Linux Kernel through to hobby projects like PCGen. Perhaps talking to their committer teams might give you some insights."
Patches get rejected from the kernel all the time for many of the same reasons listed in the linked post. It takes a long time for most new kernel contributors to get anything substantive in, and major changes almost never go in without huge reviews, fights, competing proposals, etc..
The only difference between that and what this post talked about is that for the kernel, a lot of the sausage making goes on in public (though far from all of it).
I personally think that a project with source available under an OSI Licene but no effort to respond to or build a community is not really an open source project.