I will agree with you that many times people have unrealized potentials in terms of both increasing their income and decreasing their expenses, yet there are also likely cases in which people are struggling within their own best efforts, and so they have difficulties (and perhaps even impossibilities) increasing their discretionary income.
Nothing is impossible when someone has a plan in their life and to achieve a much better financial source requires hard work by relying on existing opportunities and when we want to change our lives for the better, then every effort must be made to grow a much more stable income. The existing potential needs to be increased and at least be able to meet the needs of life and continue to try to set aside a little money to start investing.
It may sound difficult for some people who do not have a steady source of income, but it does not mean it is impossible if they are willing to fight.Com'on man, what do you think you are fighting when you have no source of income?
Anyone that doesn't have a means of livelihood has no business in investing in Bitcoin, because it would be just a matter of time before he start eating his investment bit by bit till it's exhausted, so what am trying to say is that you can only invest in Bitcoin when you have a source of income, because it's only through your source you can buy and accumulate Bitcoin consistently either weekly or monthly, but if you have no source of income, I would advice that you look for a job first, so that you can take care of your basic needs easily, after that, then you can think of start investing, because in other to be successful in your Bitcoin investment, accumulating consistently and holding without tempering with it for a very long time are key things that needs to be done if you want to be successful, and you can never achieve that if you have no source of income.
I think the emphasis was on not having a steady source of income and not that the investor will not have any income. Income can come as steady income and unsteady income with the first being what many people understand as suitable for Bitcoin investment through the DCA method since it makes the calculation of the discretionary income as well as the emergency funds easy. Little do many people know that even with unsteady cash flow, an investor can still work the entire process out in such a way that he can make investment and still set aside emergency funds. It is just a case of doing a little estimate of how likely there will be cash inflow and work with that on calculating what should be the discretionary income and the other income segments necessary to make a comfortable Bitcoin investment.