How does Whirlwind Money collect their customer’s information?
By linking the depositor's address with their withdrawal destination. Coinjoin coordinators are not trusted with their customer's data and are not trusted with depositor funds, so it's clear that Whirlwind is acting maliciously by choosing to act as a trusted third party instead.
Regular people who merely want privacy cannot be expected to setup an entire company themselves. That's nonsense.
You don't have to setup an entire company, you just have to find other peers who want to coinjoin with you.
I will still have to trust that the third party will approve our private coins afterwards.
The point of owning the private coin is so you can verify the coordinator is not performing a Sybil attack on your non private coin, there's no trust at all.
Either you are pretending you don't understand what attack vector I am talking about, or you don't understand how the software you are actively defending works under the hood.
Go ahead then, explain what attack vector you are talking about since I've already explained how the Sybil attack vector is detected and defeated.
I understand that, and it is important!

One big question mark for me (PR-wise) is why they fight critics to the bone instead of answering their questions. As far as I know, that's not how you get people who worry about the security and privacy of your product, to try it out..

What question do you have about the security and privacy of the WabiSabi coinjoin protocol? I'm happy to answer.
Besides the fact that you should stick to the topic at hand (your own service), centralized services do have some inherent advantages. Of course, a trustless solution would be preferred, but centralized CoinJoin coordinators (as you have shown) also have the ability to spy and censor.
That's not true, the coordinator does not know which inputs belong to which outputs in their coinjoin transactions, so they do not have the ability to spy like a centralized mixer does.
Please get it: no matter how often you repeat the words 'trustless privacy' and no matter how well that works for your usual audience, Bitcointalk isn't buying it.
What part of it don't you understand? Coinjoins are completely non custodial and do not require you to trust the coordinator with your data.
First of all: it's not my job to.. do your job.

I don't have to fix your product. If you want to run a successful privacy product, it's your job to make sure it actually preserves and improves privacy.
WabiSabi coinjoins do preserve and improve privacy, you can verify that for yourself: https://mempool.space/tx/d465033214fd2309dcce5a90c45fcaa788aa4394ee36debe07aad8d8a37907d2
And does this mean I have to use a different Bitcoin privacy service, to be able to use your Bitcoin privacy service?
No, anyone can coordinate their own WabiSabi coinjoins.
How do I even tell whether I have 'private coins' or not?
Coinjoin them.
Let's not forget that the option to change coordinator was hidden (even non-existing in GUI, from what I recall), at least when they transitioned from Wasabi 1.x to 2.x.
This isn't true.
Except you absolutely can't. If your coin is rejected, even if you think it is private you have no idea if you are being Sybil attacked or if Coinfirm have deemed your coins too naughty..
You would know there is no reason you could be rejected because the coin is private.