in fact entertainment is not the main reason for playing gambling. most of the people play gambling for making money and only then they can entertain gambling other wise they will feel gambling as boring game of the world. i think if some one want to get entertainment so there are so many other types of activity from where one can get more fun and enjoyment as compare to gambling.
Some people feel different about it, they want to get entertainment form it and also making money at the same time. This is a good way of doing two things in the same time, some people get lucky of course and win so we cant really blame them for what they are doing as long as they feel cool about losing money in gambling