The drop-out/expulsion rate means little - it is the number of solid priests ordained that matters. It has probably been the working of the Holy Spirit that insured we have had so few priests ordained in the US and other such countries in recent decades, given the state of the seminaries and the bishops who oversee them.</p>
So you seem to be saying it is a blessing? I can live with that. Even the trouble with some in SSPX may be a blessing. Before he died Archbishop Lafebvre was asked by his seminarians what he was praying for. He told them he prayed that all those who did not believe in what they were doing would leave the society. Perhaps he is still praying for this. Perhaps Christ is granting that prayer and the Holy Spirit is doing this good work. Better few but strong in faith than many and weak.
Seminary dropouts are nothing new or unique, I know several men now middle aged who washed out for various reasons as young men.
Its a pretty rigourous program, and its a time of discernment to determine whether or not the candidate has the right stuff.
I don't have any firm stats, but half the men dropping out just doesn't seem very extreme from what I understand of the experience, in fact a lower level would make me suspect of the school.