Very few people cheer when people lose money. If you (dear reader) do, something is terribly wrong.
Something is terribly wrong. You may recall I wrote a quick data recovery utility for deleted Bitcoin private keys recently? Well, it's not actually that hard to do - as far as I can tell, the main reason no-one else had was because most people here thought anyone that needed it deserved to lose their money, and I got a fair bit of hostility in IRC based on this.
As for the person who lost money, why would he tell his friends not to use money simply because he lost some?
That's a false dilemma, though. The choice isn't simply between losing money and not losing it, there are different forms of money with different associated risks, and people telling friends not to use one because they lost their money that way and it's too risky is part of the process by which everyone decides which would suit them best.