For all it's critics, I travelled Ryanair and noticed several seats (about 3) with the tray-table in front secured by sticky tape (the clear parcel sort, not "Gaffer tape!) the flight was fully sold other than the faulty positions, which CC informed me were only unusable because of the insecure T/T mounted to the back of the seat in front.
It was a very shiny modern plastic and easy-clean aircraft, not a converted Vickers Vimy
Lost revenue must have hurt! so full marks to RYR
Similar situationon return leg, so I assume this is a design fault/weakness.
I see little problem with a failed upright lock.....If an arrival is sudden enough for a loose seatback to cause a problem, I would expect that to be the most insignificant one in a drastically rearranged cabin.
As a pax, with a lap restraint only, I'd welcome a bit of "give " in the seatback in front, whilst bent over waiting to kiss my a55 goodbye.
Am I foolish, or just laid-back,( so to speak, ) where this risk is concerned ?