Tell me why exactly investors will rush to buy in to an under performing asset just because it's packaged into an ETF? Everyone and their hairdresser is now aware of bitcoin... if they had wanted to invest in it, they would have invested in it. Clearly, the last 9 months are telling us something: they're not.
Some investors cannot invest in Bitcoin because of regulatory concerns. The EFT enables huge amounts of money to be invested with no friction
Also: some investors won't invest in Bitcoin because their financial advisors don't recommend it, and their financial advisors don't recommend it because they can't get a commission out of selling it.