If your income is not regular and sufficient you will be forced to sell investments to meet your necessary expenses. This contradicts the basic principle of the holding strategy. In such a situation will anyone be able to face the next financial challenge? They will probably try to raise funds in other ways but that takes time and planning which is not easy for everyone.
I don't think that any bitcoin investor without a regular income will be forced to sell his bitcoin investment when he invested with his discretionary income. Some people get it twisted that you need a regular income before you can start investing in bitcoin or before you can hodli your bitcoin portfolio for long-term.
A contractor who gets contract twice or more in a year does not have a regular income because he gets his income whenever he has a contract. That doesn't mean that because he does not have regular income that he will sell his bitcoin investment for survival when the money that he was paid for the last contract that he did is still with him since he has already set out funds for his basic needs and monthly expenses from his pay. He has even set aside his discretionary income that will spread over various weeks for DCA.
Discretionary income ia what is used to invest in bitcoin in order for you to be able to hodli for a long-term and not income.
Take the 2017 Bitcoin boom and subsequent crash. Many new investors then entered Bitcoin with their savings and unknown income. When the price suddenly fell they were forced to sell Bitcoin quickly and many suffered losses. This shows that just having discretionary income is not enough; having a secure financial structure is essential.
A new investor only needs his discretionary income to start his bitcoin investment, if his discretionary income is regular that's the best because he can keep on accumulating bitcoin every week uaing DCA method to be buying consistently and persistently overtime in order to keep his bitcoin purchase ongoing which is the most important thing.
Only poor financial management and lack of proper plan will make anyone who is using his discretionary income to buy bitcoin to panic and sell. Those people that you are referring to in 2017, don't understand how bitcoin work or they also used money that was beyond their discretionary income to buy bitcoin believe to make quick profits within a short time but the reverse was the case. Bitcoin is a long-term investment.
Assuming none of them sold their bitcoin in panic, they wouldn't run at loss. Therefore, if you have a secure financial structure, if you follow the wrong step in investing into bitcoin and sell due to panic, you will still run at loss. Secure financial structure wouldn't prevent you from losses.