3. Invite-Only
As everything runs on a decentralized network, once invited it is not possible for us to freeze assets from users. So we have to take some measures to not let bad actors in in the first place. With Fairlay, some bad actors used to have several accounts and it was very hard to ban them. With Bitcoin Betting everyone can easily see who was when invited by whom.
A real decentralized system is that we do not have to login with a username and password and connect our wallets to the site and gamble / make a bet. Also by using the invite only access, how is it possible that you do not freeze accounts ? Lets suppose a good person have a account on your site and he invites his friend who is not a good actor, and he misuse or violate any terms and conditions (or make multiple accounts), so you will not ban his account ?
Actually, it is normal for us to be skeptical about these services which claim from the very beginning to be decentralized and censorship-proof. I have dealt with decentralized casinos before and other dapps which claim to have decentralized features thanks to the implementation of smart contracts , most of them still have a little back-door so funds can be added or retrieved from the smart contract by the holder of the private cryptographic keys of the one who deployed the contract in the first place.
It is a way for casinos and decentralized services to save guard their own interest and protect funds from being stoles or stuff in a faulty contract, but obviously sacrificing the decentralized nature of the service.
I ignore whether this is the case for this service as well, unfortunately, those negative feedbacks on OP's account can only make me feel distrust of the actual decentralization features of this bookie.