You're not engaging with the actual criticism at all. Nobody is disputing that "embattled" is in the dictionary; instead, he's saying that it's journalism jargon that is not actually used in real life.
No, no, no. pg is claiming that "embattled" is a journalistic euphemism for "guilty as charged". Sure, it's jargon and rarely used in "real life", but it's generally not inaccurate or deliberately misleading.
Someone who is accused yet innocent is still "embattled". Readers assuming guilt is not a problem of fact. It may not even be the journalistic intent.
For that matter, embattled is often used in a context where there's no crime at all involved. A CEO may be embattled because he hasn't been able to turn a company around and the shareholders and board are being restless. In that case, in a sense it's code for on the way out, but only because by the time you get to that point, the handwriting is probably on the wall.
I tried the word "embattled" in Google News. One of the articles that came up was about an embattled tree. Which I'm sure is every bit as guilty as the media suggests.
That, at least, is a response to the actual argument. I disagree: I have never seen a story where "embattled" was used to describe someone the rest of the story led you to believe might be unfairly embattled, and the nice thing about "embattled" is that you do not have to actually prove anything to use it. It's just "I hear lots of people are saying..." dressed up.
PG is blaming journalists for what is certainly an anecdotal interpretation of the word. There's no reason for anyone who knows the meaning of the word "embattled" to believe it's castigating.
The thrust of PG's claim was that journalists use the term as a synonym for "guilty" and in response, a journalist has argued that they actually use it in line with the dictionary definition of "characterised by conflict or controversy". A bit rich to accuse other people of "not engaging with actual criticism" when your reading comprehension falls that far short...
In my experience, journalists use it mostly for people who are likely to be fired shortly, many of whom are not "guilty" of anything other than being in a position of responsibility in an organization, department or team that is perceived as underperforming or being taken over by critics.
I actually would find embattled a bit of an unusual word choice for someone on trial for a crime outside of a broader context. If someone's arrested for murder, we'd call them a suspected murderer or alleged murderer, not someone embattled.
As you say, I associate embattled more with, say, an executive caught up in a scandal or who is likely to be dismissed for poor performance.
"alleged" or "suspected" is actually perhaps a better example of the sort of not-always-correctly-interpreted-by-the-readership journalistic phrase PG intended to highlight, since "alleged" can both mean "this person is [probably going to be] on trial for this offence, so because it's so serious we're respecting the legal process by not asserting they did it even though there's substantial or even blindingly obvious proof" or "we're just reporting something someone once claimed and because it's so open to dispute we have no desire to get sued by making the claim our own"
Someone who is accused yet innocent is still "embattled". Readers assuming guilt is not a problem of fact. It may not even be the journalistic intent.