Let me ask you this way, so what is the point of having more than 1 account then if they do not have the intention to abuse it? What adaseb saying is true, nowadays people make more account just to abuse the faucet as well, like aiming 9900x and keep doing this forever, if you do not banned this kind of abuser, your site is not going to develop as well
It is normal to have more than 1 account, but max 2 accounts. First account which is the main account is used for betting purpose and the second account is usually being used as "bank" account. Obviously if the main purpose of having multi accounts is to abuse something then it should be banned. But I know there is a dice site that lets you to have multiple accounts as long as the accounts are not self-referred to gain profit from the affiliate program.