I agree with you point @Frankolala. And yeah the same situation you said also  applies to someone who doesn't have a stable source of income. That’s why I feel that when it comes to Bitcoin investments we shouldn't even be debating on whether the income is stable or unstable, one should rather focus on the real question which is whether one can actually extract his/her discretionary income from whatever he/she earns. Because at the end of the day, your discretionary income is your deciding factor on whether you can invest in Bitcoin or not. Without discretionary income, your long term investment in Bitcoin is practically impossible, whether your source of income is stable or unstable..