The Chicago Manual of Style is, in the US, the preferred reference for most book publishers in the non-fiction field ¹.

If you are writing in some other genre, there probably is an "industry standard style reference" and Chicago is quite likely to be acceptabe, but you should check with the publisher (confirmed or potential). Quite obviously, in some fields of writing, the correct reference must be "None" but it doesn't hurt to check.

The Associated Press Style Manual is another that's widely available and is apparently in every newsrag editor's desk; but little editing seems to be done. The AP manual is much looser about what's acceptable – except in a few very specific cases, mostly where the publisher might get sued if you do it wrong.

If you're writing for magazine publication, it's almost mandatory that you know what the conventions are for the individual publisher(s) to whom you might be submitting your material. This is especially true for "technical" magazines, some of which have (or have had) some rather "arcane" requirements. Many of the more respected(?) magazine publishers may have in-house editors to clean up things for you; but others may expect you to meet all their rules from scratch.

A factor perhaps in the "grad students who can't write" is that most schools, where a thesis is required, have their own "thesis style specifications," and it's not uncommon for each school/department within a university to have "unique requirements." Students who have spent time and effort conforming may "just assume" that their thesis represents style and methods applicable everywhere. While quite obviously this is often not the case, their thesis may actually be the first thing they've ever written that was subject to "critical review" [with the obvious possibility that they may have been forced to conform to "personal preferences" of an idiotcynicratic professor who was assigned as their thesis advisor].

It appears that the main complaint in this thread though is not about the lack of style, but about basic illiteracy. No arguments on that.

¹ This may be a rather loose categorizing. It is quite well known that Microsoft Press claimed to use Chicago, at least quite recently. While the enforcement of "style" there obviously isn't too "tight," the real question is whether Microsoft publishes "non-fiction," which can be quite legitimately debated.

John