Yes there are many people that relys on bitcoins as their main source of income but i think most of them are people who didnt have that real decent job to work with so they came up to bitcoins.Students are one of them, including me bitcoins help me to earn for my school
yea i also tell that many people don't source btc income. i think trading is best source of btc income.
other a lot of game that give btc income opportunity any one can earn that's way.