playing basketball and being a student athlete would be my guess as to why.
If you were having a blast you wouldn't leave a year early for a tough transition in a new country where you make OK money.
Now why aren't they having fun? Could be a ton of stuff.
Team Chemistry?
Coaching Staff?
Success (this is almost certainly one)
Bad games in smaller gyms?
Brand of basketball?
School being too difficult to manage while playing?
Tons more I'm sure