@A_0123456 You make good points (and counterpoints). After thinking a bit longer, I now think the issue in this specific case has another layer of subtlety. (I admit, this post might be reading too far into the situation.)
The user in question definitely has a pattern of behaviour which people have come to expect. A lot of his posts followed a kind of "format": if analyzing a game, for example, he would point out mistakes, leave comments on those individual moves, quote famous players, and say little else besides. Lichess has terms of service which, while occasionally a bit vague, are not hard to follow in general, and none of tpr's posts that I have seen ever came anywhere close to violating those terms of service (unless there's something I missed in the TOS). As someone who has been on the forums for a long while, it's utterly inconceivable to me that he actually violated the TOS. By which I mean, I literally cannot think of what he could have done; to violate the TOS would surely require behaviour so far outside of his modus operandi that it's really hard to believe it actually occurred. I think other people in the same thread have the same reason behind their shock. (Edit: While I was writing this, sarg0n made their post above this. They make a fair point.)
And yet, lichess - or, the mods representing lichess - is asking us to believe it occurred. Implicitly, community members are being asked to choose who to believe: a single visible person, who they trust on the basis of thousands of publicly available forum posts; or a group of invisibles, who claim to be acting for the best but refuse to reveal their intentions or even hint at their reasons.
The fact is that even if tpr has done something wrong, lichess's own policies have put them in a tough situation when it comes to retaining the trust of their userbase. I'll believe them when they ban the accounts of titled players on the basis of opaque statistical analyses; I'll believe the fact that the mods generally do good work, and that the site would be much worse off without them (probably it couldn't even function without them!); I'll certainly believe them when they say that lichess and all of its services will be free, forever, for everyone. But that tpr is in the wrong here? That one gives me pause, to say the least.
I admit I do not have a constructive suggestion for how to improve this. Just trying to clarify why this has caused such a ruckus.