Honestly speaking I don’t think there is anything wrong if an investor choose to invest all his discretionary income into bitcoin, considering that you have taken care of your expenses and you’ve an emergency and reserved funds, if I choose to invest all my discretionary income into bitcoin, instead of using it to extravagance lifestyle of buying cloths and during drinks and cigarettes and clubbing, at this point of my accumulation stage I think there is no need for such lifestyle.
I would prefer using my discretionary income to buy more Bitcoin and be more aggressive instead of using my discretionary income for some unreasonable and unrealistic activities.
Investing aggressively is good but to an extent, just as you have said if you have taken care of all your expenses and still got an emergency and reserve funds them you are good to go , you can invest aggressively into Bitcoin and stack up your portfolio instead of wasting your discretionary income in an unnecessary things that you may look back and regret tomorrow, but since Bitcoin is a long term investment I would advice you invest with your discretionary but not all so it won’t result to you selling it , you can just invest little by little and before you know it , you have got a good portfolio.
A person level of aggressiveness all depends on the amount of discretionary income available, they can’t go outside the line meanwhile if the backup fund is set it’s a free will to invest aggressively but, make sure you’re not doing too much when you need to save up more emergency and reserve funds alongside investing. One thing about buying aggressively it must not always be regular, honestly we have different financial crisis and yours is different from mine or unexpected situation just comes up reason we should invest knowing our capacity to further investing for a long period of time like 10 years plan.