Playing for money, to me, isn't the equivalent of choosing music as your profession.

A lot of people play for money, make and sell CDs (more now than ever before), and none of that is what I consider being a "professional musician". To me, a professional musician is someone who makes their living from music, not from accounting (which is what Paddy Maloney of the Chieftains did for a decade or so before the Chieftains went pro) or some such.