Suspect the ACM rationale as simple as 0/90 seats? Or worse?
NoD
They were 0/90, but the primary reason was that the anticipated escape route would have been through the "flight deck", the canopy was to be jettisoned prior to touchdown. Rapid egress from or over a live seat could have lead to an even more rapid egress! I suppose that a secondary consideration, as Jig Peter mentioned, could have been to remove the risk of inadvertent operation during the "arrival", but I am not sure about that.
YS