IMO, greed is the factor here rather than trust (I am not blaming him for being greedy, we all are) as he is trying to portray here by describing FBC as a bank. There has to be some sort of interest (or some promised tokens) which FBC promised, otherwise it does not make any sense to not hold keys to your money.
I also feel sorry for his loss as it is not his mistake, FBC broke the agreement and decided to scam but it will surely serve as an example for future investors.
Wouldn't call it greediness, more like giving too much trust to Freebitco.in. Back in the days when this site had perfect reputation, I remember some people even used it as their hot wallet.
When they introduced interest thing, I always said that you shouldn't keep more than you afford to lose, no matter how much you trust Freebitco.in. Not your keys, not your coins - we already had way too much stories with trusted sites falling.
I followed this rule too. I still have some BTC on Freebitco.in. Somewould call it significant amount, but it's not life changing if I would lose it