Although the usage may well be rather ancient, it seems the application of the title "Father" to secular priests in English speaking countries is a recent (couple of hundred years, max) innovation.

Regardless, the practice, whatever its age, does seem very strange given Jesus' "divine command" in Matthew 23:9--“Call no one on earth your father, you have but one Father in heaven.” 

We certainly cherry pick the "divine commands" we choose to take seriously. At every mass, we hear the command to "take and eat" and "take and drink" but are content so very often to merely "take and eat." For the life of me, I don't understand why parishioners don't demand the chalice in parishes where it is not offered, and so often walk by the chalice where it is offered.