Bitcoin is not my only source of income. Infact I consider bitcoin not as a source of income but a store of value with potential for future increase. So, I do not even think twice about why I hold.
I just buy and forget about it. It is like buying gold or any other precious metal that you fancy. You buy it and keep it and turn your focus towards something else knowing that it can never depreciate in value. Despite the volatility of the market, my confidence stems from the fact that it can never go to zero.