As for KYC.
I think sportsbet.io has KYC
Yes, to the best of my knowledge this reflects the KYC policies or Sportsbet.io. But is it that bad? It's only for big transactions, and IMO this makes perfect sense. Or are you a person that wants to bet more than 2k EUR and still go unnoticed and unidentified?
Just think about it. At least with Sportsbet you won't end up in a situation like with Betmatch, because the former has a strong reputation and works hard to maintain it. You can see that they have negative feedback related to a story that occurred 2 years ago, but the issue was actually resolved and one of the two people who left feedback related to it is, unfortunately, dead, so it's not possible to change it.
As for your Betmatch case, I think you should make a Scam Accusation or at least a thread in the Reputation childboard to attract more attention and warn people.