And, around 30 years before that, all the theology classes would have been in Latin. I'm not saying we should go back to that, but it's amazing how much we just shy away from any suggestion of rigor in seminary formation.
Parish priests do not need to to be Classical Scholars. If they can discern a bit of Latin, that ought to suffice.
I'm not sure that that squares with Sacrosanctum Concilium--the laity are expected to know all the ordinary prayers of the Mass in Latin, as well as a number of the common chant modes. For that to be possible, all priests should be trained reasonably well in Latin (4-5 semesters of it at least).
It was as recently as 1962 that Pope John XXIII issued his encyclical "Veterum Sapientae" that required and demanded that all seminary courses be given in Latin. Fluency in Latin was a pre-requisite before you could even begin seminary. That document has never been officially rescinded. But Vatican II by some mystical power has rendered moot everything prior, even if it was prior by only a matter of weeks.