There are a lot of players around the world. Not every games are favorite in all region. Some likes soccer, some maybe esports or some cricket or others.
Which one are you mostly placing your bets on? Besides, do you think gambler don't care which sport it is. I have seen gambler who don't have any fucking idea about cricket but he used to bet on cricket.
There are two factors to consider why a gambler gambles and/or place bets in sports.
1. Expertise (or a sport they often play) - They are passionate about that sport and loves to just gamble teams in a field of sport they knew more about - those that already knows a certain sport often tend to have more winrate as they have both motivation and knowledge on each and every aspect of the game and its players, even the momentum and current news with the team's actions. Most of gamblers that lies in this factors are those that bets only on a certain game or even a certain game in eSports (as eSports doesn't really need to be knowledgeable with the all the players and teams worldwide, just events and tournaments would suffice and be a reference to a better gambling decision)
2. Money - these are those people whom you know that bets regardless of what sports either knowingly or unknowingly. They often relies on bets and just the current news, or even their gut feeling, for their bets - as they only preferred enjoying how their gambling
Basically, its not a matter of what sports. It's the matter of what gambler are you in sports gambling.