The Recline was to get the seat in the jet... that is the primary reason. On long ferry missions not much pressure is on your sit bones and back.
G tolerance and endurance is about hitting the gym.. not really the 30 degrees of recline :)
Also ejection out of the jet.. which can be career ending... youyour knees have to clear that dash on the way out... so they had to make sure the seat gets you clear of the suns-shield /dash and the vertical tall as you are fired toward it...