If anything, it shows how hare-brained schemes can end up. In contrast, Mata Amritanandamai has in her temples proved that caste is not an inhibiting factor for anyone with an aptitude and necessary training for priestly functions. The kind of devotion and following that she gets is proof of her ability to penetrate the caste barriers of Hinduism. The reason why she has succeeded where the other two experiments failed is because her actions have the sanction of the community to which she belongs. That is how Hinduism has flourished for thousands of years.
Tradition has a lot more to do with priesthood than education.
Given the various traditions prevalent in Hinduism, it is indeed difficult to standardise priestly vocation. I have seen in some of the great temples of North India, worshippers entering the sanctum sanctorum and pour over the idols milk, ghee, Gangajal and other offerings while, in the south, they are kept at a distance. There is little in common between the practices of the priests in these two traditions. It's not just a question of geographical difference as the rituals vary from temple to temple. It shows how difficult it is to standardise a course in purohitya.