A lot of research has been made in this direction by the PaX team/brad spender of grsecurity. In fact, many of these techniques were first implemented on modern kernels by that bunch. However, political moves have always clouded that -- pax/grsec is run as a project of passion and not as a day job, and therefore there has always been reluctance to deal with those (and get involved in sometimes very territorial code review/maintenance sessions).
Unfortunately, by not really crediting or even acknowledging this research (and also ignoring a lot of work thats been happening in academia on hardening commodity kernels and applications), the Linux kernel is a)playing catch up to other operating systems (instead of adapting newer techniques) and b) alienating researchers even further.
grsecurity offers commercial support, and customer-only stable updates. (Only the latest version of the patchset for the latest linux kernel is available at no cost.) (Of course, if you pay and receive a stable update, you can re-distribute it under the terms of the GPLv2.) grsecurity is not a hobby.
A lot of their work has not been accepted into the mainline linux kernel ... but it's hard for me to see how this is a problematic sort of "not really crediting or even acknowledging". If anything, it pushes people to go to the source, grsecurity itself, for their "hardened" kernels. It seems that grsec/pax do have a lot of recognition as a result.
Yes, the inventors and developers of these hardening techniques want to be praised and have their work immediately used as-is to save the world. But we don't all have to want the same thing, to have the same priorities. We don't all face the same threats, nor performance and feature requirements. If people want to make the various trade-offs in favor of a significantly more "hardened" kernel, they've been free to use grsecurity or openbsd for quite a while. No need to blame linux-mainline maintainers for the people who have not made that choice. There's really no unfair lock-in going on here...
Unfortunately, by not really crediting or even acknowledging this research (and also ignoring a lot of work thats been happening in academia on hardening commodity kernels and applications), the Linux kernel is a)playing catch up to other operating systems (instead of adapting newer techniques) and b) alienating researchers even further.