People who has a day job usually makes the bitcoin world as their side line. They wanted to have multiple sources of income. People who are doing bitcoin in full time are mostly people who are people who basically can't get a job for some reasons. Although not everyone who's full time on bitcoin are uneducated, there are some people that chose to make Bitcoin as their day job. Maybe because they are earning much more in bitcoins and they want to focus on it, and they just see their previous day job as a disturbance to their bitcoin journey.
I think the person who doing full time in bitcoin for now is those jobless people, and they made it a temporary source of income because they cant find job for now and thats really good since bitcoin is here, but for those who have job i think they are those who is innactive and making bitcoin as past time only.