One reason is because most parishes are being run as a business, with the priest as a CEO. There are more lay people running the parish which reduces the priest to a caretaker. He has very little authority as the laity tell him which preface to use, what the homily should be and what Mass he is supposed to celebrate. To quote an old maxim there are too many chiefs and not enough Indians.
Actually worse than a caretaker - in this part of the U.S. the layman in charge is called "administrator" whereas the priest is merely labeled "sacramental minister." In other words, "Father, just say Mass, pass out the hosts, and move along"!