One would assume it would be quite attractive to become one if he enjoys gambling. One gets to participate in the action and make money no matter which horse wins -- as long as they manage the edge right.
Being a bookie would be fun if you like maths, are street smart, somewhat not highly ethical but you are disciplined and can control your emotions. Similar to poker I guess. And are knowledgeable about the sport with respect to odds not trivia.
I doubt a typical gambler would enjoy it. Does a "foodie" love working in a lab testing flour samples?