Up to this point, you have only provided input and a blinded output (no Sybil attack is possible)
The sybil attack is an on-going process. If the coordinator forbids you from joining the round, with the excuse that you're "naughty", it gains the advantage to replace your potentially untraceable coins with traceable, to de-anonymize certain inputs; which are the victims of the attack.
So let's just assume it's only me and you trying to coinjoin this round
That's quite of a big assumption to make. In reality, you don't know anything about the people you coinjoin your coins. That's the reason we're discussing about sybil attack in the first place. If I knew by whom the round is consisted of, I wouldn't have to worry.
Note that I am talking about the possibility of the coordinator using the power that other attackers don't have to perform sybil attack, what you described in your previous post could be achieved by anyone, I know the maximum number of inputs in each round is x, I can register x inputs and perform the same attack, in other words, this could probably be applied to all conjoins coordinators not just ZKsnacks, so not sure why is this an exclusive criticism for Wasabi?
A sybil attack is obviously not an exclusive perk of Wasabi; it can potentially be executed on every peer-to-peer network. However, comparably to e.g., Joinmarket that's implemented resisting measures such as
fidelity bonds, there is clearly an orders of magnitude difference. Not only does Wasabi not resist same like, but it requires approval from an entity that is incentivized to execute such attack.
You're also making the wild assumption that the remaining clients will be concerned about experiencing a sybil attack. Anyone choosing to use Wasabi after the extensive list of red flags would be the least likely to worry about being sybil attacked.