The RAeS article makes relevant points but it seems much of the research was done through BALPA, the same outfit that advertises SSTR schemes in it's journal and is unwilling to confront the "pilot mills"/ "approved schools" that promote such schemes (possibly because many of it's members work for the schools part time as TREs/TRIs......).
P2F will end when it becomes too expensive for wage slaves to get loans or (sadly) when accidents happen.