Numerous cases of backdoored wallets, or poorly implemented weak private keys generated from javascript, or straight up theft from deposits.
While a tiny aspect of dealing with Bitcoin is secure (key pairs) [1], actually using Bitcoin has proven to be a mess for almost the majority of users.
This is not a user friendly experience for most users.
I assume he meant people have had their coins stolen, usually from exchanges, really not much different than your bank getting robbed, although in this cause your money is gone and the exchange doesn't cover the theft.
There is no FDIC for Bitcoin exchanges. Also a distressingly large percentage of the exchanges to date have been either fraudulently or incompetently run and lost the user's bitcoibs and/or fiat money.
Nobody would use banks if 4 out of 5 were completely cleaned out by crooks and went out of business.
While a tiny aspect of dealing with Bitcoin is secure (key pairs) [1], actually using Bitcoin has proven to be a mess for almost the majority of users.
This is not a user friendly experience for most users.
[1] https://lbc.cryptoguru.org/about