Starting in the 11th century Pope Gregory VII started to enforce celibacy. The demand for celibacy came from the masses who were tired of priests being more concerned about making money for the family or finding nice positions for the sons than tending the flock. I remember a history book about that the era. People would drive away what they saw as corrupt priests along with the real or fake wives.
Thanks for confirming one of my basic points:
That marriage among the clergy was common practice for many centuries before compulsory clerical celibacy was institutionalized.
I think reasonable can discuss the issue, debate it, and have differing views on it. In our archdiocese, we have a number of married priests (mostly converts from the Episcopalian Church)and they do just fine. So do Orthodox priests for that matter and Catholic priests in Eastern Europe and the Middle East where Catholic clergy are permitted to be married. No one has any issues with it.