My understanding is that the integration work for these huge academic patchsets, took up the lion's share of any time the maintainers booked as "working on JIT." If not, these patchsets at least got in the way of useful progress in JIT work, redirecting "work on JIT" into themselves; where progress gradually slowed due to the "big ball of mud" that each of these patchsets were; and then all such progress was lost when the patchsets were given up on altogether.
