Because there are just not enough people that is same power as you do to playing sport fight! So the system just hook you up with people that are available at the time. We just don't have enough players for several reasons
#1: Too afraid to fight... Keep living up with fake Success Rate
#2: Players that farm alternative ( farming dummies acc), this is against the Term of Service which can result in a Permanent Ban immediately
#3: Big level people being mean... ( Yeah, not all of them, but a lot of them do) and it makes people think... Why die to make them happy, starve them off... xD
#4: We just don't have enough players xD People give up too quickly...
Well, those are the reasons I can come up with... But I am sure there are a lot more to it. How to fix this? Encourage everyone to go fight more! Big level meet big level, small vs small. Then it will be fair game