~ Going against the crowd or, in other words, betting on something that is very unlikely to happen, has nothing to do with the amount of money someone can afford to lose. In many cases people lose more when they go with the crowd, because the payout of such bets is small, and in order to win $10 you have to wager over $50, and in the case of bad luck you lose your $50. While if someone aiming to win $10 going against the majority, he/she can risk something around $2, and either lose it or win $10 in case of good luck.
I think going against crowd is not a big deal if you have a good observation of the scenario on which you are going to put a bet. But if the case is opposite and you don’t know anything about the case and
just by believing on your luck, you make a bet, I think that would be a big mistake from your side because sometimes there are things that are cocksure that they will happen and without thinking and putting bet can never change those things.
A big mistake? I don't think so. A big mistake is thinking that something is definitely going to happen. Actually, many people lose big money exactly because of such way of thinking. They bet $1,000 on a team that, according to the majority of bettors, should win the game, being absolutely confident that after the game they will be $100 richer(1.1x multiplier), and lose $1,000 because of bad luck. Haven't you read such stories on this very forum? I've read tons of them.
If the vast majority were always right, anyone with $1,000 could stop working and start living off sports betting alone. But the reality is that you are very likely to lose at least one bet within 10 bets with 1.1x payout, and thus your overall profit will be slightly negative.