As one of the 2 people I can say for sure it happened to, I have good reason to be confident in what I'm saying. I also have good reason to not just post the records publicly, though. I've got sufficient evidence to support everything I'm saying, and have provided it to relevant authorities. Sharing the kind of personal information in a public space is... less appealing to me.
As for your claim that I should keep my grievances personal, well...
I've literally had one of the *VERY* few people who seemed remotely competent in Steam support tell me to "make my voice heard", and I've posted every one of these claims in spaces where they're clearly visible to Valve, directed at them publicly, and *WOULD* be grounds for a defamation claim if they had any basis to make one. The fact that it's true is part of the reason they're being investigated for their conduct, and I'm not being taken to court over my own *FACTUAL* claims. Because telling the truth is an absolute defense against defamation.
You and I are both well aware there are methods for sharing such correspondence without DOXXING anyone. In my opinion, the harm potentially being done is EGREGIOUSLY worth the risks with a little censoring of personal information. And I'll repeat myself, and I say this with no malice: without evidence, your claims are paper thin. By all means, make your voice heard, but if you're telling the truth, do so with your whole chest. Otherwise it's just farts in the wind.
By spreading the word about this the way I have been, I continue to occasionally find people who are being harmed by this problem, but aren't yet aware of the cause. I continue to see evidence that my voice is being heard and paid attention to, and that it's actively helping others. And I continue to see developers (not all those I speak to) who are willing to take appropriate steps to ensure their games are more widely available than Steam exclusivity will allow. Telling me, even if somewhat less rudely than you could be doing, to shut up, isn't productive for you OR me, so if anyone needs to take your advice at this stage, it's probably you.
I have multiple reasons not to be sharing the documentation I have in public spaces. You've addressed only one of them, and not very well. In some cases, redacting the details which are needed to avoid publicly sharing someone's personal information leads to redacting information relevant to the topic being discussed, and/or information which would be needed to giv the documents any validity as proof of the claim in the first place. The people for whom the documentation is actually needed, have access to it.
There are plenty of reasons unrelated to my own for why some people are avoiding Steam (DRM, occasional blurring of the lines on fraudulent conduct, the removal of useful features with the excuse that being more popular than steamdeck means nobody's using them and somehow that justifies extra work to remove things they could just leave intact without harming anything), just like there are plenty of reasons why other people still use Steam and will continue to do so (convenience, easier communication with devs than a lot of other options, btter support for early access projects in particular). Regardless of how large each group is, and regardless of their reasons for the decision, there are growing numbers of non-Steam-using PC gamers, and having *SOMETHING* available as an alternative is always going to be an advantage over being exclusively locked to a single storefront.