You might be on to something but there is a little bit more to this because when going to the sportsbet.io website from the UK the URL gets diverted to sportsbetio.uk and there are lots of terms and conditions they have to abide by including very strict UK laws with them being based in the Isle of Man.
The website "sportsbet.io" itself has largely nothing in protection for the end user with their organisation based in Curaçao "mBet Solutions NV (Kaya Richard J. Beaujon Z/N Landhuis Joonchi II Curaçao)" and states "It is licensed and regulated by the Government of Curaçao under the gaming license 1668/JAZ."
Maybe sportsbet.io is under some government pressure since they have some big sponsorships and everybody has their eyes on them so they are trying to eliminate any kind of risk whenever possible. Just a possibility and a shitty one...