On fungibility. I guess the debate here comes down to the question: is it fair to say that Wasabi is making bitcoins fungible? AFAIK it is: Fungibility, sometimes called interchangeability or indistinguishability is a property of good money. Two instances of a currency are fungible - interchangeable - with each other if there are no meaningful differences between them: they have no marks, nor history. That's exactly what Wasabi Wallet coinjoins are doing. Two coinjoined coins are indistinguishable from each other. It doesn't matter which coinjoined coin you have. That's fungibility between two instances of a currency.
You’re not looking at the issue holistically. Fungibility includes all Bitcoins in existence, not just the ones your service lets trough. It’s possible to separate between coinjoined and non-conjoined coins. Coinjoins alone dont solve the issue. By introducing Blacklists you’re already starting to take part in the issue by starting to separate between coins yourself. Accepting all coins equally is what is necessary to make a contribution to fungibility. Bitcoin is already fungible, it is services introducing the nonsense and separation. If this childishness doesn’t stop then it might be necessary to make it impossible to separate between coins on a protocol level, which im not entirely a fan of. Humans just can’t handle this responsibility apparently. For Bitcoin to succeed all coins need to be treated equally, i don’t see how it’s a smart business decision to weaken the foundation it’s built on.