Earlier quoted context omitted.
So, I think it is a perfectly valid apology if basically the only thing you regretted about your actions was that it made someone upset This is what makes it a non -apology.
No, it doesn't. If you say something that offends somebody, what else is there to be sorry about? It's not like you killed somebody and offended somebody else, and are only apologizing the offending part. When you offend someone, that's the only bad thing that happens. Or, as comedian Steve Hughes puts it, nothing happens when you're offended.
In this case, a honest apology would be one where Dell apologizes for hiring that moderator: if we could go back in time and hire a moderator again, we wouldn’t hire that person.
Maybe their apology for the offense is supposed to imply that (presumably, since they are apologizing, they want people to not be offended, one option for them to prevent that is to not hire people like that in the future), but why not say that directly?
(I think the view that offense doesn’t matter and can be safely ignored is extremely damaging. And besides, it’s not as though offense is the worst thing about this. Dell gave someone the stage who legitimizes very weird views that would be disastrous if they became – even more – widespread in society or even the basis for policy. That’s why people are offended. And that’s a very good reason to be offended. Yes, words do matter.)