First, let me say again that the tone of a passage is not relevant to the formal cogency of its arguments. Someone who confuses the two things is not discussing tone intelligently.
But think about Catherine Deveny recently being sacked from her column with The Age for saying, on Twitter, "I hope Bindi Irwin gets laid." (She also made another remark that contributed to her sacking. That's not relevant to my point, and I confess that I find it harder to put a charitable interpretation on the other example.)
Now, there are lots of things that might be said about Deveny's now-notorious tweet. E.g., it might be said that it was unfairly picking on, or making fun of, an 11-y.o. girl. We could discuss that separately, and I think there's a bit to say on both sides. But what can't be said, by someone with an intelligent sense of tone, and language more generally, is that Deveny literally meant that she hoped 11-y.o. Bindi Irwin would have sexual intercourse with someone after the Logie Awards.
To understand the tweet you had to model the assumptions the
You have to imagine sitting watching the TV with Deveny, or sitting at the table with her at the Logies, as she makes a whole series of mordantly humorous, vaguely snarky comments. Then a famous 11-y.o. girl walks past wearing a sexy "glamour" outfit. You both, perhaps, share the idea that such outfits are not appropriate for girls that young. In any event, you're certainly both aware of the issue. Deveny looks at you in a certain way, and says, drily, somewhat disapprovingly, "I hope Bindi Irwin gets laid." Perhaps she reinforces the effect by rolling her eyes or giving a quick, meaningful glance in the girl's direction.
As a result, what she really communicates is a sort of half-amused, half-despairing disgust that such a young girl has been dressed up in such sexy clothes. It's almost as if someone has styled and clothed this sub-adolescent female person to display herself to potential sexual partners. Or so Deveny insinuates.
People who didn't "get it" have accused people who are trying to explain the above of merely rationalising, but I don't think that's remotely true. We're explaining the message that anyone reading Deveny's twitter feed, with the context of the Logies and a knowledge of Deveny's modus operandi and what was going on, would have picked up.
The way she expressed the message doesn't make her argument against what she sees as the outrageous sexualisation of an 11-y.o. girl either more or less cogent. But the way she said it drove home her point that there was, as she perceived the situation, something ridiculous, and something creepy, about putting clothes like that on someone so young. So there was a reason to say it the way she did (she was, of course, also restricted to 140 keystrokes).
Furthermore, in the aftermath of her sacking, the debate about whether she said something that was a sackable offence, etc., its's a good idea to have an intelligent understanding of what she was communicating and why she said it in the way she did. Many of the people baying for her blood either lack this or are being disingenuous.
Of course, Deveny didn't think all this through consciously at the time. It would have seemed a natural way for her to make her point. As we all do, she has a kind of tonal repertoire that she calls on more-or-less automatically. Nor did people who "got" it have to think all this through consciously as they read their Twitter feeds. But we can't now have an intelligent discussion of what she meant, whether she was justified in putting it that way, and so on, without being able to think through and talk about tone and related aspects of language in use in social contexts.
So yes, I want us to be able to discuss tone with some sensitivity and intelligence. I think that judgments about tone can be important. That doesn't mean I'm with the gang who attack every author they dislike for allegedly taking a hostile tone ... rather than discussing the cogency of the authors' arguments. But it does mean that there are many ways, in many contexts, where tone matters, and we should be willing and able to discuss it.