Firstly, athletics is universally loved! Having the other continental championships not on the same level as the European one, doesn't mean that those continents don't like the sport. On the contrary, it's one of the most popular sports worldwide, as seen on every World Championship.
Then, i don't see how the Prediction Contests are only for Europe, when from 20 or so contests in the calendar, only 2 are European continental - the Water Polo one, and a handball one in december, when, let's be frank, there aren't many big sporting events in december. If you don't count the Darts World Championships though, which i'm totally inclined to have included. All other contests are worldwide based, open to all countries and are usually chosen, because they will be some of the most famous and anticipated sporting events, which can bring the most users to participate. And every year there have been included some less know stuff, like sailing and equestrian this year, to not have repeating contests.
Also, why do you even need the prediction contests to stay on the forum. They are a fun little side thing here, with hardly any bragging rights. You can always talk and contribute to the events and sports that you like, and i'm sure you will be surprised that there are other people to have a similar interest like you.
Even though the forum is yes, overwhelmingly european, there are many people with very different tastes in sports, which can't be seen on many places. You can't blame us, europeans, for being interested more in the sports that are most popular here. After all, these are the events, the athletes, the traditions that we are most acquainted and interested in. I would very much like to watch more badminton, because it is a sport that i'm very interested in following, but when it is shown only every 4 years on the TV here and you have to dig deep for a low quality stream to watch and can't get invested in the athletes, it is really off-putting.