The Catholic Church does have married priests. Our Eastern-rite churches have always allowed married men to become priests. Our Latin church requires celibacy but dispenses from this when married ordained Protestant ministers and Episcopalian priests are accepted into our priesthood.
Celibacy is not essential to the Catholic priesthood; but it is a long-established spirituality that supports the sacredness of marriage and human sexuality. Priests who are whole, happy and pastorally zealous can be a challenging sign in the community that even a beautiful family is not the ultimate value. In turn, married couples are signs to us priests that we must not be selfish bachelors but rather people lovingly and sacrificially committed to serving the larger community. Together we seek the Kingdom of God above all.
However, the life of committed celibacy does not fit with every Catholic who experiences a calling to the priesthood and whom the community validates in that calling. They are excluded, and this is a loss. Moreover, we mourn the departure of many fine priests who have left the ministry only because they discovered that they could not freely and joyfully live a celibate life.