I agree, depending on the daily activities we do, we will tend to develop certain aspects of ourselves and certain ways of thinking over others. Nevertheless, this doesn't mean a profession determines the personality of a person.
What you tell me about the incapacity to express negative feelings is more common that one could think, negative feelings are mostly about vulnerability, and sometimes we for the most part don't want to look or much less, be vulnerable, so what do we do? we block the things that make us feel like that. The negatives feelings you mentioned like
sadness, grief, anger
are hard to express if we are not with people we truly trust.