Is this a US thing or what? Don’t keep money you may need in the short term (< 5 years, at least) in stocks. A stock ETF is not low-risk, cash and bonds are.
I'll admit that I definitely should have done more investigating on my end, and I'll take my share of the responsibility on that, but that doesn't absolve the Winklevoss twins and SBF from responsibility. An "obvious" scam is still a scam.
EDIT:
Just to clarify, I actually agree with your point. It's good practice your short-to-mid-term savings in FDIC-insured savings accounts, bonds, and treasury bills; basically stuff with nearly-zero risk. Since the fiasco with GUSD I've been saving my shortish term stuff in treasury bills specifically for this reason (and because they're a bit more tax efficient in a place like NYC).