Yeah, that's bubble-specific, not class-specific. I think the most successful of the younger professionals I know are most likely to gamble on sports -- it's an excuse for an active group chat, it's something to talk with random people about, and the actual amounts you bet are easy to make trivial relative to income. Very networking-forward hobby. (Also, it's obviously as much an intellectual exercise to gamble on sports as it is to play poker.)

Broadly, though sports in particular is something different bubbles care more or less about, I'd say your perspective is entirely foreign to me. My experience is that the more intelligent groups I'm around are vastly more interested in predicting things and putting money behind their predictions.