The strongest force, it seems, that keeps academia in Latex is that it is required, literally, by the publisher, as the scientist's end result.

I think that's false. The author's claim is that "inertia is why we still use LaTeX"; I think the strongest force that keeps the publishing community in LaTeX is that it does a hell of a lot more than HTML.

For people who are reading papers all day, typesetting matters. If I need to digest a difficult concept, I don't want to spend any brain cycles at all on bad formatting, because I want to spend all of them on the content. The HTML experience today isn't capable of producing something readable when I'm at full capacity with the paper's content, and I suspect that reviewers feel the same way.

So, no, "a simple alternative" doesn't exist, sadly.