* If I have a position, I'll want to convince everyone that I'm right because it'll make me right (if everyone thinks energy stocks are worthless, they will be.) That's why most people with lots of skin in the game, long or short, are very happy to publicly argue that their bet is correct.
* Someone very risk-averse can think, correctly, that he's likely right, but loathe the 10% probability to lose money. Conversely, someone can be near-addicted to gambling and make bets based on very little, or someone can just be wrong regardless of their risk preference.
Overall, a random commenter's arguments seem more interesting to me than their claim to have bet on being right, even if I trust this really hard to verify claim.