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.
If you already have an emergency fund and reserve funds, and so on, it would be great to use them all to buy Bitcoin. Of course, if you use them all to buy BTC, you'll have a lot of BTC and ultimately, you'll reap significant profits in the future. However, if that's your choice, it's certainly extraordinary and wise. Many people use discretionary funds for various purposes, such as buying BTC, partying, and other things. Honestly, I admire you if you're able to use discretionary funds to buy BTC.
But personally, I don't think I can do that. Sometimes, when I have discretionary funds, I prefer to use them to buy BTC, and I also like to use them for other things, such as partying, buying clothes, and so on. I believe entertainment is also very necessary, and having fun is also very important.