Doctors make decisions, somewhat, based on medical facts about how the body and it’s organs work — so should marketers and business people.
Like a doctor, marketers profession is understanding, explaining, predicting and influencing body physiology — specifically the organ of the brain as it determines behavior.
Subjective, everyday experiences and everyday/natural language is no more useful to a marketer than a doctor.
To understand and treat any medical conditions, reports about emotions and conscious perceptions are minimally informative and much more likely to be misinforming. Why should it be any different for marketing and business? Tests are the norm. In fact, any doctor who depended on self-reports and everyday language would soon kill patients and be guilty of malpractice.
A bunch of people getting in a room and making decision based on swapping opinions, platitudes, case studies and the most powerful people, the clients (“patients”), is no more useful than using the same tactics to decide medical treatments.