Earlier quoted context omitted.
I think the truth is somewhere in between. If someone wants to write about what they've done for writing's sake, then fair enough to go the extra step of posting a blog about it. But there are plenty of blogs that seem to exist because the person first decided they wanted to have a blog and then came up with something to write about. Not SEO spam, more like résumé spam maybe? Those are still awful to wade through on…
I've always wanted to write a blog but never dared to do it because I feel like I have nothing of interest to add to what already exists. Now after reading that article, I feel like I could indeed start a blog, and there would be a good chance that it will be boring and/or low quality, at least at first, but it would be my content and I could be proud of it. If I hold myself to a high standard that makes me want to o…
Maybe it's not the motivation for the blog but how it's distributed that can cause problems? If someone writes a half-arsed article about what they've recently learnt about C++ references, for example, then posts it to /r/cpp where everybody already knows that stuff better than they do - that is annoying.