Actually, a steady income is a MUST for saving a part of your salary in Bitcoin, especially if you employ a DCA sort of strategy. Because it doesn't matter what you call "prepared", if you don't have a steady income then you definitely ARE NOT ready.
I disagree with you because a steady income is not a must before you can start investing in bitcoin, what You need to get started with bitcoin is your discretionary income. if only you can map out your discretionary income from your main income for the week or for the month then you can start accumulating bitcoin and hold for long term 5 to 10 years or longer.
If you are teaching newbies that a steady income is must before they can start accumulating bitcoin and hold for long them you are misleading which can delay their investment journey. Because teaching newbies that steady income is must means that they need to have a hudge amount of before they can get started with bitcoin which is wrong, all they need is a discretionary income to get started with bitcoin.