Borrowing money from the bank to invest in crypto is essentially betting on which asset would appreciate more, a currency which suffers from inflation and has unlimited supply or an asset with storing value + utility. So yes, it would be weird not to do it.
If he borrows and invests in a bitcoin and the market is a little dumped for a while, how will he repay his loan? We know the potential of Bitcoin which is a market dump but we don't have much tension. But when someone invests that money by borrowing money and the market suddenly dumps that investor will be under a lot of pressure to repay the loan. So in the case of this type of investment, it is necessary to make money which will not be a big loss even if it is lost.
Investing in crypto is not something easy and the risks are also big so consider again before borrowing money to invest,
use cold money and I think it's the most appropriate thing,
the crypto market is really difficult to predict if we are not careful anytime we can lose money
Invest on what you can afford to lose and dont ever consider on taking up some loan just to invest on crypto because it would not really give out any assurances or guarantees that you could make out money
of those investment and if you do mainly rely on it then you would really be putting yourself into trouble thats why on the time that you do make out investment then it would be good that you would really be
spending or investing the money which is just an extra or savings of yours but of course dont go all in with this one and only invest on what you can afford to lose.