Even if you assume that it's a raw number and is also reflecting increased adoption of automatic transmission it's kind of hard to blame a huge 8x multiple on solely the oil without something else to corroborate it (like sales figures for wet clutch and brake friction parts used in industrial applications which would be subject to the same increased wear if the oil was sub-par).
Transmission fluid isn't special. It's basically just yet another variant of hydraulic fluid. The hydraulic parts of a transmission pretty much never have problems relative to the frequency with which the friction parts simply wear out. So other oil running clutches so see the same increase in failure rate over that time.
Assuming the number itself is accurate OEMs producing designs with additional gears and lockup converters with the bare minimum of refinement (ship now fix later type engineering) in response to the fuel crisis probably deserves some blame.