I'm guessing this is in large part due to a generally low level of knowledge about how gambling (and particularly online gambling) works. At the time of my first encounter with Bitcoin gambling (Satoshi Mines) I was also quite ignorant but it took me ~10 minutes to figure out the probabilities. I'm still mystified why some people don't want to learn how gambling works and at the same time are willing to put a lot of money on their wrong assumptions. Let me know what you think.
I so agree with you, man. To add to this I think some people are either not aware of the probabilities involved in the game OR they might be too emotional driven persons that act on impulses. That's where the addiction comes from - they don't act logically when gambling away their money although the statistical/mathematical/scientific/facts are against them and clearly proving that they are going to lose on the long term..