it is rare that somebody is happy after gambling, ~~~
Absolutely, there are very handful individuals or gamblers that win and go happy after gambling. Most of these guys are cheaters of the system before they could have a win. Although, sometime i gamble and win and go happy but not a big win, but win is still win, so, people still win with varies amount.
This means that not all of them loose in gambling. This would not be incorrect to say that gambling being a world of uncertainty really makes you vulnerable and prone to loss. The house edge is often the reason in addition to many others which includes low knowledge about the game you are playing and the lack of experience of gambling out of anger or emotions. This lead many people to loss and hence only few money.