Music is not the only field in which the majority either earn very little or undertake the activity without pay. Most actors struggle to earn even an average salary but many amateur dramatic societies produce fine performances. Artists have always struggled and may find their best earnings only appear when they are dead.
Talent is not enough there needs to be a demand for what you have to offer. Folk musicians will always struggle as the demand is so small. To earn big money become a folk rock band, get a record deal and sell to a wider audience; hey presto Mumford and Sons are now multi-millionaires; Simples!
john