Bitcoin can function as a source of income, mainly for those working for big BTC companies, Like Bitpay, Coinbase or even large casino and gambling websites, having teams working, However for traders and for buying/selling altcoins, it's very subjective and unstable.
yes it is a source of income , i am one who will be a proof of it, bitcoin helps our family, long time ago we dont have anything to eat except for the foods that we have in our plate, my parents doesnt have any money to buy medicine but now we can afford that , i can now support my family, i dont need to get outside the house to earn money.