Priests being celebate has been a tradition over the last 1,000 years and I think it's a good tradition. A priest is married to the Church so a priest should remain celebate. Why change it? The priest has enough obligations, why should he have to worry about a wife and family?
The question is somewhat misleading. The Church has never allowed already-ordained celibate priests to marry. However, the Church has always had provision for ordaining married men. These are two separate categories. It's possible to support one (on the basis of Tradition) without the other.