There's an inverse side to that "anyone": professional scientists are under pressure to publish long scientific-looking articles, and their fellow reviewers have almost no motivation to spend any significant time reviewing (no pay, no nothing, just a small non-quantifiable reputation penalty for declining to review).
Whereas most scientific bloggers post things they are interested in and therefore feel have something to say.
professional scientists are under pressure to publish long scientific-looking articles, and their fellow reviewers have almost no motivation to spend any significant time reviewing
You have a point but from all scientists I know myself there's not one for which this applies. Might depend on the field though and I'm not denying there's a bunch of impossible-to-reproduce-crap published and there are rotten apples everywhere. But what I see (in fundamental research which is usually not as publicly known as other kinds) doesn't come near what you describe, even though it's anecdotal of course.. Yes there is pressure to publish but their papers aren't 'scinetific-looking', they're properly scientific and they are just the length needed to describe the findings on the subject. And there is an abundance of motivation for reviewing mostly inspired by wanting to make sure everything is as correct as possible, for the sake of research.
Thanks for the balancing point. My experience describes applied research in such "hot topics" as computer vision and machine learning, and many people, myself included, are more interested in getting the technology to work and apply it in real commercial projects, where paper publishing may seem like a price to pay for research grants subsidizing your R&D.
These grants are aimed at building a working technology and strengthening national economy, so there's nothing wrong with the approach per se, but when your reviewers share your values they have little motivation to find every possible mistake in your paper, at least for second- or third-rate journals (which are still indexed in WoS so are perfectly enough for the funding agency).
Whereas most scientific bloggers post things they are interested in and therefore feel have something to say.