Since JPMorgan is lending against Bitcoin by keeping it as collateral, JPMorgan's decision may be a relief for Bitcoin holders.
Because there are many people who are constantly hoarding Bitcoin but sometimes they need a large amount of money that cannot be covered by their emergency fund. Then, Bitcoin investors are forced to sell their Bitcoins.
JPMorgan's lending against Bitcoin may keep the Bitcoins of such Bitcoin investors safe.
If they ever need an amount of money that their emergency fund cannot cover, instead of selling Bitcoin, they can take a loan from JPMorgan against it and repay those loans by earning money later.
Also, when Bitcoin comes to DIP, even if they do not have enough funds to invest, they can enrich their portfolio by borrowing from JPMorgan aggressively by buying Bitcoin.
you also forgot the main advantage
loans are not taxible
so giving coin to JP and they give you cash(as loan) is not hit by cap/income tax
if you dont repay loan, they keep the coin, which on your end is like selling the coin (coin->cash) but the tax man end is tax free transaction
(this is not financial advice speak to a financial specialist to understand full details)