I’m a construction worker and unfortunately cursing is as normal on the job as breathing. For most of my career, I thought nothing of it, it was just part of my day. But as my faith grew and my faith matured, I began to see it as a real problem. I mean, how could people see holiness in me if they heard me talk like that? How could I evangelise? And most importantly, how could I walk like Him if I used foul language to communicate?
So last Lent I gave up cursing. I did OK, but I slipped to often and when Lent was over, my old habits came back. I failed. This Lent, having matured another year in my faith, I have tried again and Blessed be God, I am doing great and I know that God is going to see me through this time!
Not to make excuses, but the rough and tumble nature of my industry led me and most of the others to cursing. What would lead a highly educated priest to curse, I don’t really know, so IMHO, a priest should never curse. Maybe a slip, maybe, but never in general conversation. He must be held to a higher standard, because he is our faith leader and like the OP felt, this can be a big turnoff.
Hey, if I can clean up my act, than certainly a priest should be able to!