That's exactly what I wanted to hear, thank you. You don't know! You (as in Wasabi and zkSNACKs, not you personally) have no idea what are good and what are bad coins. You don't know the reason someone isn't allowed to improve their privacy. They don't tell you. You accept the decisions made by Coinfirm without asking, hey, what exactly is wrong with those UTXOs?

Why would a company that preaches openness accept unknown rules and requirements by someone that doesn't explain to them those same rules and requirements? If there is such a thing as dirty bitcoins, don't you think everyone should know what that is and not rely on some weird entity that presents that information to you for whatever reasons they think they should?