As a yankee that moved to the south for a while before retreating to Seattle, I can say that my reaction would vary based on the local culture. There are areas where it seems EVERYONE is a pastor and enough of them are preachy and/or judgmental enough that, yeah, it's a conversation killer. The constant barrage can also make you hypersensitive. I didn't much care until after a few years of living there, but by the time I left the constant "have a blessed day!", the bumper stickers, the billboards, the email signatures (even from state govt employees), most any personal local story in person, in writing, or in news...I mentally flinch if something gets near the topic even though I used to not have much reaction at all.
I imagine 'doctor for souls' is intended to show humor and approachability, but as you say, it would not work that way for me.