Too many would try to "catch a falling knife" as the saying goes in the stock market. A 90% correction wouldn't be that unusual, but it also wouldn't stay down for very long (with perhaps one exception). Last June, ETH had a 99.999% drop for about 10 minutes when it went to 10 cents due to news of Vitalik Buterin's death. Then it went back up to where it was.
It helps to know what's possible in the tech field. 90+% of all cryptos are really just forks with a skeleton team of IT dev's (or just one dev). That's the big difference between bitcoin and practically every other one in the field. No other coin can say they've had hundreds of developers scrutinizing the code. For that reason Bitcoin is much more secure.
Bitcoin has had a long history of being counted out (check out bitcoin obituaries). Once other coins start achieving scale, if they do anything other than copy bitcoin's repository (like BCH's one dev does), then they'd better start hiring fast or be left in the dust.
Another habit people seem to have is animating a coin as if it had some consistency in it's identity or a "soul". Bitcoin has changed so much that one would scarcely recognize the code as it is now compared to 2009. I bring this up because the label bitcoin is the most sought after in the field. If the original maintained mostly by Blockstream dies, then the focus will shift into a new team of devs who pick up the old label. Bitcoin Cash is just waiting for this to happen.
I predicted over a year ago that Bitcoin would be in a relatively static phase from Feb 2018 - Feb 2019. I have reason to believe that we'll see the mooning of that label again from summer 2020 to early 2021. The next time this happens, the volatility will be considerably less because of the massively increased volume of trade. Right now bitcoin is a dingy in the Pacific ocean, but it will be an aircraft carrier by 2021.