Prenominal vs Post-nominal #3

Even in childhood I  noticed that some specific degrees seemed to come with the use of a prenominal honorific while others did not. Dentists and medical doctors were typically introduced as "Dr.," while pharmacists and attorneys rarely were accorded a prenominal honorific.This can differ by country and sometimes even by gender. Recently I was introduced to a couple like this:  "I'd like you to meet Dr. X and his wife Y.'  Both of them had doctorates. Hmmm. On a trip overseas I was introduced to a different couple as "Harry and his wife Sally." That was followed with, "They are both physicians at our regional hospital." I found that to be an interesting distinction between WHO they were as individuals and WHAT they did professionally. What makes the difference? Does it reflect the perspective of the individual doing the introducing, evolving societal norms, unthinking habits, all of those or none? Having said that, the individual being introduced, audibly or in writing, may have had nothing to do with how he or she was presented. Not long ago I was introduced as speaker for the occasion with these words, "Arlene is with us today. She's a nurse." (And I was with them, in person, no less. LOL!) It's all food for thought...and often fascinating . . .