I guess I'm just not seeing how it makes sense to describe missing out on an unexpected windfall as a failure to "avoid complete financial ruin".

Like, if I have $N of equity in my house and it burns down and it's not insured, then I've just lost $N regardless of what is or is not in my bank account. IMO there's really no comparison between that scenario and missing out on winning $N because I didn't buy a winning lottery ticket.