Never heard of this one in particular, the same race that I know of is marble races which are streamed by some Twitch streamers. This one looks fun I have to agree and I think that it will be a fair race because I do not see any hamster trained or bred to be a racing champion which means that a house pet hamster could be a champion. You also have to consider the hamster ball.
I heard about this one from a guy who actually wanted to see how his idea will work and posted here , I literally never knew it would become big. The hamster is happy and I do think this would not only make her more engaged with her owners but people from all over the world can count on her. The only thing I am sad about is that they are using ETH and not BTC but then again it's easier with the transfer fee and such.
Plus the hamster has been taken care of and I did looked though their site , it's not like mia is running on the wheel for a long long time. She does get rest ! Apparently the next bet is like 11hr away so it's a good thing that they are giving her a considerable amount of rest and taking care of her health.
Now see this is way better than gambling of cock fighting , on horse races ! This is indeed not harming anyone.