First and foremost, in the Roman Catholic Church, it would open the floodgates to allow into the Roman rite priesthood, a raft of men with no real vocation who have been impertinently banging on the door and demanding admission to the priesthood on their own terms rather than those of the Church. The National "Catholic" Register is filled with the whining of these chronic malcontents. So are such cesspools of collectve dissent as Call to Action and Voice of the Faithful and their many counerparts.
Just as they do not wish to obey the pope in respect to the traditional vows of the Roman rite, many, many, many do not wish to be in doctrinal submission either. We have ostensibly celibate priests who are rank dissenters now. Their numbers would be substantially increased if there were a general allowance of a married priesthood in the Roman rite and the Church would sustain yet more long-term damage.
The RCC allows married priests in its much smaller Eastern Rites and admits to the priesthood in the Roman Rite married men who have served as clergy of the Episcopalian and/or Lutheran Churches (who must be ordained anew). These are not permitted to marry again after ordination and the apparent reason for the exceptions is one of charity and recognition of pre-existing obligations to wife and children.
A pedophile is a pedophile is a pedophjile. A homosexual exploiter is a homosexual exploiter is a homosexual exploiter. Some of each are married and some are not. Our basic rule is that homosexuality is an INHERENTLY disordered condition (always Catholic belief) and that no one inclined to homosexuality be admitted to the priesthood (according to orders of the very liberal Pope John XXIII).
Our secular newspapers reveal regularly the failure, particularly in English-speaking countries, and most particularly in the whacko liberal precincts of the leftist AmChurch (American liberal "Catholic" "Church") of Church authorities to successfully prevent the ordination of homosexuals and other perverts just as they gleefully thumb their collective noses at Vatican orthodoxy generally.
Normal men are normal men and do not seek out other men as objects of their sexual desires, must less the newspaper boy or the altar boy. For most of us, we can remember fathers who were not casting a fond glance at the hindquarters of the neighborhood 12-year-old boy or of his twenty-something brother when mom was out of town or otherwise unavailable. Dad married mom because he loved and wanted mom. BARF ALERT: No 12-year-old boy will serve as an adequate substitute. Adultery is not a norm much less so is lavender adultery and even less so is lavender child-molesting adultery.
Whatever Hugh Hefner may imagine himself to think, men who vow lifelong celibacy are neither unrealistic nor warped. Their worship is reserved to God rather than to their body parts or those of others. Somewhere in America is a college student who plays football very well but has decided not to play so that he can concentrate on his engineering studies.
The priesthood is also consistent with an ethic of sacrifice (an important part of the priestly vocation is offering Mass) and Catholics generally see moral merit in individual sacrifice of immediate pleasures. We are famous for not eating meat on Fridays, fasting and abstaining from nourishment to some degree during Lent, et al. That is not a way of life that is encouraged by the Reformation but it IS the Catholic way of life.