That flow chart seems pretty reasonable to me. The big one is

"Are the entities with write access having a difficult time deciding who should be in charge of the data store"

The vast majority of pointless blockchaining come from organisations that have already decided that they are going to be in charge. Which is just great for them, but it doesn't induce others to join them. I wonder how much of promoting blockchains is to project the illusion of relinquishing a degree of control. I guess all the ones doing it just because others were doing it are looking at AI now.