this kind of thinking is like saying "look at those who lost tons in stocks during the financial crisis! This is why I never invest one cent in the stock market".
The Beijing Olympic made $150 million in operating profit alone, despite the gigantic cost, not to mention what a boost to the city's economy, employment, image and global status. The effect will be long lasting.
Considering the cost, Beijing hasn't been immensely successful in terms of pure profitability, however, we all know China basically didn't care about the cost and only focused on impressing the world at that time. Atlanta 1996 and Sydney 2000 had a much smaller budget but reaped $877m and $230m in profit respectively. Actually Athens is the only one what lost money in the past 4games.
Opposing the Olympic Game just because someone lost money before is like deciding not to make any investment just because stock price may fall.