Open Source Security (the company behind grsecurity) is still existing, so it's got enough customers to support the grsecurity developers (both the ones we know, as well as (presumably) PaX Team).

It seems to me like grsecurity aren't interested in upstreaming their patches. That's one reason (among others) why their patches are distributed as one big file, instead of (for example) a patch set or a Git branch.

Why are they not interested? Well, it seems to me like Linux devs may not have placed as high a value on security, when compared to other metrics (such as performance). I understand what it's like to be advocating for a position, not finding acceptance after a long try; finally saying "screw it" and going their own (commercial) way.

So any 'debate' related to grsecurity is going to include people (including LWN commenters) who feel very strongly against grsecurity's position, and how they should be more open, and free, and willing to compromise (if that's the right word) to get the grsecurity/PaX Team patches upstreamed.

And then you have very strong personalities in the kernel dev community. That makes compromise very difficult.

It my opinion, it's the same reason why having a conversation related to politics is nigh impossible: Your strong views affect what you say, how you say it, what you hear and how your perceive it.