Luna was the gas token of the Terra chain. UST was the algorithmic stablecoin built on the oracle price of Luna. People did not doubt it was risky. What happened what there was differences of opinion on (1) the fundamental demand for block space on terra (which was the fundamental value of Luna), (2) the speed in which UST unwind it's market cap into Luna liquidity (no cooldowns or mechanically delayed minting), (3) the amount of protocols that hard coded UST = $1. I personally never participated in the 20% anchor cause it didn't pass the smell test. I also never held Luna or UST. I did end up with an infinite amount of Luna against my will when Blizz Finance on avalanche enabled it as collateral and the oracle hit its minimum price allowing someone to empty out the entire market. Anyway, I did *also* overestimate the fundamental demand and underestimated the wind down speed possible. So yeah, you can be smart and still be uncertain on how known mechanics will play out in a worst case scenario.