...you assume there are many of these users who are banned that will switch to your coordinator, right?
Who knows how many there are. Wasabi and zkSNACKs doesn't keep records, blockchain analysis isn't going to publish anything, and those who got banned from participating in a coinjoin, for whatever reason, aren't going to complain publicly in great numbers.
Besides, you can always outcompete zkSNACKs by charging lower coordinator fees or by offering different round parameters that better fit to certain use cases.
Why don't you do it for example? Are you personally happy with the route zkSNACKs has taken with the censorship? Do you think there should be censorship like this?