I think the far larger factor and simpler answer is that Bitcoin is still being viewed as a high-risk asset. As such it gets the boot first when managing risk.
Yes I'm sure that is a significant factor. And yet it's also considered a long term asset, so jumping out when the market moves (as it will of course) seems odd.
Two possible explanations:
(1) Many investors don't really see Bitcoin as a long term asset yet. This is probably due to the fact that it is still a relatively young asset class.
(2) Investors trying to re-renter the market at a lower price point, assuming that Bitcoin continues falling based on its relatively high volatility.
Of those two I believe (1) to be the bigger contributor; and the only solution that, I'm afraid, is time.