This is not about whether or not sex is good. The Catholic Church teaches it is indeed a good thing. The priesthood however requires a complete donation of self to the service of the Church, and this is made difficult by having a family. It is no wonder that the eastern rites of the Catholic Church (which has married priests) have asked the Latin rite to maintain the discipline of priestly celibacy.
So, here's the thing. I'm an atheist, so I'm probably not the best person to be commenting on this particular question. That being said, I'm very much a proponent for sticking to what you believe. Priests take certain vows when they enter the priesthood. These include poverty (ahem) and celibacy. If you believe everything your Bible says, and want to do everything your Bible says, and want your parishioners to do the same, then you need to follow your vows to the letter, not just the parts that suit you, in my opinion.
A Franciscan priest named Rohr once said that sexuality is and most likely will always be the central issue for men. He asserts that male sexuality cannot easily be sublimated and I think I cannot entirely disagree with him. It seems as if forcible celibacy was a contributing factor to the sexual abuse scandal in the Church.
The Church has allowed married men to become ordained longer than it hasn't. They stopped allowing it over property reasons, but now that reason is irrelevant. If priests wish to remain celibate, which most always have, even when it wasn't necessary to, then it is their choice. But a lot of the times, priests are asked to give marital and parental advice. I know most priests are well meaning and want to help, but what advice can a single man offer a couple? It would be more helpful to have a married priest give the advice.
But overall, there's no reason a priest cannot run a parish, and be married at the same time. Yes, both are demanding, but it has been done before, and now that married former protestant ministers are allowed to convert and become ordained, people can see that married men can in fact make good priests. I think the church should rethink its policy, seeing as Europe and North America are facing a priest shortage, and a bad one at that. It makes sense, especially since priestly celibacy is cannon law, not docterine. It can absolutely be changed, and it should.
The human body thirsts for physical activity which includes touching, sex and orgasms. I feel the body and mind would suffer it could not relieve stress through sex or even emotional love. A person cannot dedicate their lives 100% to one profession because without a break or vacation they will go crazy. Also, the sexual abuse by these "celibate" priests is absolutely disgusting.
Very few people in the world are actually capable of being happy without sex. Why force an entire profession to abstain from sex? Even from a Christian, perspective there is no biblical scripture that holds that celibacy is more pure than sexuality. Even Paul wrote that his views of celibacy were merely his opinions.
If a priest feels called to remain celibate, he should. Otherwise, all priests should be free to marry and have children if they want. They should all abstain from casual sex, and sex outside of marriage, but there is no reason man cannot be a husband, a father and an effective priest.