Bloomberg had an article before the big game on how amateurs and professional bet on the Superbowl. Amateurs like lottery ticket type payouts - bets that pay off in low probability situations. The two trades highlighted in the article were "Will there be a safety" and "Will there be overtime?"
Thanks to the first play of the game, amateurs made out well if they bet the first score would be a safety (or even if there would be a safety at all). But it was yet another game without any overtime. The amateurs pushed the overtime odds from a 13 to 1 payout to a 6 to 1 payout - and despite a small point spread it didn't even come close to paying off.
In general, the favorite trades of retail "investors" are either even odds or ones in which they risk a little capital to make a lot. In general, risking a lot of capital to make a little bit just doesn't seem fun or safe - even when the probabilities are in the investor's favor. It's also a lot more fun to make or even read about high payoff bets than it is to look at all of the bets that didn't pan out.
And while these bets are often negative expected value, they can sometimes make money. Plus, having money riding on random events can turn a boring game into something interesting. So while retail bettors are going to lose money on average, maybe the bets aren't negative expected value after accounting for psychic benefits.