The grsecurity team does have some valid criticisms of the upstream community, and of course they've done some brilliant technical work, but spender is unfortunately a pretty toxic community member who puts many upstream kernel devs to shame when it comes to ability to flame.
It's a shame - there's a lot of good stuff in grsec/PaX, but I think the upstream community is better off without the people involved. The KSPP effort to upstream grsec/PaX features is, of course, a good thing.
[disclaimer: upstream developer who lurks on kernel-hardening]