I think that emotions are the thing that hook people for a game. The joy, excitement or even stress before winning are what people seek. In rare times when I gamble, I seek for "Aaahhhh!" moment in every game. For example in popular game such as mines music plays that "Aaahhh!" moment, when it makes a little pause before opening a new tile. Or on plinko, I like how I just got hypnotized when lots of balls fall down and I try to predict where each ball will go.
I get you... that happened to me recently! I was playing "San Quentin Xways", NoLimit provider... when you get some big payout in the bonus round a big guy starts throwing money and yelling "Show me the money, show me the money"! It's a moment worth waiting for!
I guess if a game is good it will provide many emotions, it's not a game if we always win, sometimes trying to be better, pushing, problems solving, leveling up... and the rewards that come after are what we searching far!
Plinko is probably one of the craziest gambling games ever! I like to play with many balls and to wait for some big hit... and that big hit comes sometimes!