Entertainment is in the mindset. For instance, sport is entertaining, but hysterical fans get to cry or feel moody over a missed opportunity that led to losing a match. Over the period they'll worry about this, but months or years later they'll look back and laugh over it. However from the point of view of gamblers, their mistakes rarely allow them a time of transformation; turning it to a fun factor. It remains a lifetime sad memory for most players. Possibly entertainment has to do with an enduring memory of fun and laughter over a mistake or good deed. If a gambler doesn't have this recurring memory of constant happiness coming from his gambling experience he's not getting enough entertainment through gambling.
I think it is not only that Entertainment is in the mindset but it is the expectation that drives the entertainment. For example, you go on to watch a football match and if your favorite team wins only then you are happy otherwise you are sad or have no emotions of happiness.
If we talk about gambling then it is also related to the end result of the gamble, If you win, then you're happy but if you lose, I do not think anyone can be entertained because he lost money. So again it is the expectation that drives entertainment.
There are things that do not involve money like having a get-together with friends and family. In those cases, you will find most people entertained because there is no such thing as expectation or loses from such events.