To a degree you’re correct about CSS frameworks being “The wrong target” in that they are a symptom of the larger issue of poor HTML knowledge.

But they are a blight upon web development that do need to be addressed because the people who MAKE them aren’t qualified to write a single blasted line of HTML. This is painfully evident in every example and codebase used by them, and the very nature by which they work. (presentational classes)

EVERY blasted example of things like bootcrap or arsebreeze are devoid of the most basic of semantics, separation of concerns, and at times even valid accessible structure. When these systems that nubes and rubes are blindly copying that actively encourage bad practices, and oft telling visitors to the resultant pages to go plow themselves, you have to put them in the crosshairs as part of the problem.

Even if they were in fact caused by the lack of respect given to HTML, because those maintaining it as a “specification” seem to refuse to treat “content creators” as the first class citizens of web development. The W3C “specifications” really are as to blame as the framework creators in this regard, as they end up sending people looking for third parties to explain it.

… and when predatory scum-bucket dirtbags like W3Fools (W3Schools) are in the mix, it’s hardly a shock people end up thinking about HTML completely wrong.