As for the whole doc-damaad syndrome, my parents and sis have always had this preference. Sister because she thought it would be easier for them to relate to each other. Parents, purely for prestige. They did consider proposals from other professionals too but they always had this bias that doctor > other professionals.
Aaze, maybe you don’t live in a densely populated desi area, so these things are new to you. But trust me, there are plenty of people with such preferences.