While your quote can be true, like most quotes, it's more complicated than that. The other huge factor is where are you in terms of retirement/accumulation vs preservation of your investments. Those who are in the accumulation phase and +10 years from retirement and have a sufficient emergency fund are just throwing away significant gains by pulling money out of stocks right now for the "impending crash", which may happen tomorrow or next year or in two years or never. If my investments lose half their value tomorrow, what do I care when I don't need them for 20 years? If the crash isn't tomorrow, literally every single day the market is up I'm losing potential gains. This isn't being a pig, it's being strategic and understanding math and compounding.
Now if you're in preservation mode then it's a totally different discussion. If you just need to feel some sense of safety, it's a totally different discussion. Either way, the key is to understand you're leaving significant gains on the table, and that's fine, it's your life and money, so long as you realize what you're doing.