I agree with everything you said, yet it still remains important for guys to accept that they do not need to have perfect systems in place or perfect thoughts about bitcoin investing and/or cashflow management, since it is likely that many guys come to bitcoin from different places in terms of their discretionary income and their various skills. so surely they are likely going to be learning along the way and also making mistakes along the way too.. even if they likely are not purposefully trying to make mistakes, but sometimes they still might have to try various ways before they are able to find a reasonable balance for their own financial and psychological circumstances.
The mistake some folks make is that they feel their discretionary is too small to start up and would rather wait till they get better pay, increment in salary or promotions to boost their discretionary before starting, that's not the right approach cause of the opportunities they'll miss out on, we can all see that the numbers are increasing lately and while waiting it could increased from that point let's say $120k to about $150 or more before they boost their discretionary to the desire figure they want, so instead of waiting it's better to start small, slow and steady and build the portfolio gradually as the number goes higher. Then when things fall in place they can still boost their discretionary, do the lump-sum if possible and stead up their accumulation, Bitcoin investment is not a competition every investor should set their priorities right, start according to their income and available discretionary then know when to go slowly and fast, if they can find a balance to building a good portfolio in the future regardless of how financially strong they're then much mistakes won't be made.