I totally agree with you, there are folks that has stable source of income but getting a reserve funds is difficult talk more of discretionary, some folks are so useless and careless and yes your kind or type of income doesn't stop you or anyone from Investing as far as they get a discretionary from that source of income and also emergency funds because this fund is very vital when it comes to investing and holding for long. The only disadvantage of having an unstable source of income is that one won't be able to invest intermittently because sometimes this funds can waste time before it comes but a wise investor will device a means to make everything work perfect with the unstable income, it is all about the mind and target.
Its not a compulsory immediately you start having a stable source of income you should start reserving funds and having a discretionary income. You should know that some folks just started having a stable source of income, he has a lot to fix up. For instance, he dont have an apartment, no home appliances and other things that could make him more productive. He has to fix those things first before thinking about starting an investment. There need to be some freedom and flexibility when you start your investment. Its not something you rush into just because you have a stable source of income.
You're right it was beginning to look as if it is now compulsory for someone who just secure a stable income should starts investing in Bitcoin immediately,Although he might still venture into Bitcoin if he has an available discretional fund even without first having securing a source of income. I also think the mindset of tagging someone as useless and careless by some folks because he hasn't started investing in Bitcoin after securing a source of income is also wrong. In as much as investing in Bitcoin is very important towards achieving financial independent/ freedom in the future but there are provoking words we shouldn't be using in discussing Bitcoin for the sake of newbies. I also agree that someone who just secure a stable source of income will have to sort out his personal necessities first then whatever extra cash is left can be used to buy Bitcoin