Betting on games that you don't have much idea about can be very risky but staking low can be a way to play safe because the chances of losing is very high.
Why we should bet on the games that we don't really understand? If we have no idea on the games, it is better to ignore them. So far, I never try betting on the games that I'm not familiar enough. Besides the chance to lose higher, it is also less of fun. I think most people must choose the games that they have a bigger chance to win. And we probably prefer to bet on our favorite games.
I don’t know maybe some people are more interested in playing in games they don’t know that much about so they can surprise themselves if they win. But the amount of money you will lose will surprise you as well. Maybe they think it’s so easy to guess a bet in a sport you are not familiar with.