Because it's not particularly fair to ask an adult head of household to give up the only job his education and career history suit him for purely for a disciplinary stricture which exists solely in the Latin Rite. It's like telling him that his children have to suffer for him to convert.
(I'll note parenthetically that these situations seem to be developing their own rite separate from the Latin Rite, as the details of this case bear out.)
And 99% of the advocates of a married priesthood draw zero distinction between an unmarried ordinand and a married ordinand, as if a married man becoming a priest and a priest becoming a married man are equivalent situations, when historically no apostolic branch of Christianity has ever accepted the latter.
Very true. Even the Orthodox require that unmarried priests remain celibate after ordination. That is certainly a constant tradition.
But, let's face facts. The vast majority of young men eventually seek out marriage. Realizing that he would have to marry before seeking out ordination, perhaps a young man would seek a level of maturity before making the decision to marry or remain celibate. Of the 22 seminarians for our diocese, 15 are over 30. If all of these guys are ordained, few will leave.
I'd be in favor of making 30 the minimum age for ordination, or even 35, if the Church is going to continue to insist on mandatory celibacy.