That's actually not the case. Applications for rural churches are down, true, but there are more than adequate numbers of Protestant ministers of all denominations who apply to serve in urban congregations.
The vocations crisis in the Roman Church is tied to a lack of fidelity; simple as that.
If that's the case, why are the numbers of men being ordained to the permanent diaconate running at TWICE the number of men who are ordained to the priesthood every year (800 versus 400)?
It is simply not true that Catholic men don't want to serve the Church. It is true that they don't want to serve the Church as celibates.
God always gives His people the results of their actions. He always allows them to suffer do to their stupidity (in the Catholic Church, it begain in the 1960s, and in some quarters, continues until this day.)
Why does God seem to approve of married priests in every other Rite of the Catholic Church except the Latin? Are we Latin Riters the only "stupid" Catholics?
On the point of the Diaconate: Those in the Diaconate cannot say Mass or hear confessions. One could have 8 million members in the Diaconate, but it wouldnt change the fact that they cannot say Mass or hear confessions.