> Microsoft's wrongdoing is meaningful at least to me because I will be more cautious if I'm ever being approached in a similar way.

That's the thing: Microsoft approaching the author has nothing to do with the wrong attribution. And I am not sure if the original author here is frustrated because of the wrong attribution or just because they would have hope money and fame from the fact that Microsoft reused their code.

Because it's not like Spegel lacks visibility (given the numbers they shared in the article), the link on Peerd's README is probably not bad for Spegel, and the attention here is publicity again. Probably infinitely more than if Microsoft had done the attribution correctly.

Only the author knows about his motives.

Your point seems to be that the author should not have written the blog post and done a PR instead.

My point is that whatever the authors motives are and whether he did a PR or not, his blogpost was informative to me and has value on its own.