This is a good informed summary, thank you. I asked the same question of my Alzheimer researcher friend, and he gave a pretty similar response including aspects like the huge computational requirements and the basic non-similarity of rNNs and ANNs (albeit with a disclaimer that he wasn't in the field).

Nonetheless, I look forward to seeing more simple rNNs being created over time (besides the C. elegans one that was modeled recently). Who knows what strange organizational rules or structures we will discover from this strand of research?