It is doubtful to hear that a player can enjoy losing, no one likes to lose, losing always brings disappointment, even if the bet amount is insignificant for the player. Another thing is if for a player gambling is a way to distract himself from other concerns, but this is definitely not entertainment, it is a search for stronger emotions, that can switch attention to something else, for a while. And those players who can earn money in gambling are very few, I think only a few percent of the total number of players.
Players who use gambling to forget their current life situation are like some alcoholics. They may end up in compulsive gambling because they wouldn't want to face reality. Being this type of gambler can be very risky. Yet, many players fall into this category and quickly get disappointed when gambling isn't favorable. Imagine if they begin to feel sad over their losses. That means the player won't have any other activity to run to when having a bad day.
Majority of gamblers are alcoholic, drug takers, smokers and so on, specially for the gamblers who partronize land based casinos more, a gambler who is any of this mentioned substances will always run to it anytime gambling fails him or her, it's that simple..
But for the gambler who isn't into any of such, but have treated gambling as a means of getting away from their life issues, this is indeed not good because, when ever gambling fails to make them excited, maybe because they have lost money they really did not plan to lose, then it's dangerous because such a gambler may likely fall into depression, which could lead to alot of health related issues and even suicide if the depression is not attended to on time..