No, it doesn't. It means that the people Linus has to say harsh things do are being unprofessional--because, as Linus himself said in the quote given in the article, when he tries to say things kindly--"Please don't do that"--people don't listen. If those people were being professional, they would realize that when Linus says "Please don't do that", they need to listen.

The article even acknowledges this:

"If you really have trust and conviction that your peers are not wasting your time, you pay attention when they say something - a “please don’t do that”, to quote Linus’ example, ends up being one of the more strongly worded pieces of guidance you can get."

So the problem isn't Linus, it's all the people who don't take the time to realize that it's not a waste of time to pay attention to what he says--so he has to shout to make himself heard.

Build a community that doesn't have that problem, and people will respect disagreement and "don't do that" without the accompanying toxicity.

The Linux community is not built around flames and attacks. Linus' flames are what get public attention, but that doesn't mean they are the majority, or even a significant minority, of all his communications. He has explained many times exactly what the conditions are under which he will flame--basically, that a kernel developer does something that he has already explained many, many times should never be done, like breaking userspace. Do something that meets those conditions, you get flamed. Don't do something like that, and you don't.

I'm also aware of projects to do more formal analysis of various FOSS communities, such as FOSS Heartbeat.

But in the meantime, the plural of "anecdote" is absolutely "data" for sufficiently large values of "plural".

I disagree, but I doubt we're going to resolve that here. To me, "the plural of anecdote is data" means "I can't be bothered to figure out whether the information I have is actually representative of the population".