When I do offend people, I often like to probe as to _why_ they're offended. In my experience, most people seem to be incapable of defining any concrete reasons as to why a given statement is offensive other than circular, "it's offensive because it's offensive" reasoning.
I imagine you're capable of understanding why they might find it offensive and acting accordingly depending on the context, which is the real issue. Whether YOU find it offensive is just beside the point, as it's a given that a person doesn't stand around saying or doing things that they find offensive. Whether you're capable of evaluating the other person's point of view is the key. (I bet you probably are)
If you can see why they'd find it offensive and continue doing it, you're pretty much by definition being an asshole. That's not a moral judgment, I think it's just descriptive...
I think if someone said "Could you stop using words containing "e"? Such words hurt my brain." I think I would.
If someone said "Quit your "e" words, you bad guy!" I'd be less inclined to. "Words with the letter "e" are bad words, and you need to stop using them" even less (the difference between these two being hypocrisy).
Either way, I find it highly unlikely that I would even try to craft e-less sentences, regardless of how offensive someone might find it.
If someone finds my breathing offensive, am I an asshole if I keep breathing?
I'm specifically ignoring the action of the companies, the firings and all that, because honestly, while I haven't heard the specific joke in question, it really doesn't sound offensive to me, and it seems as though Adria just decided to be offended by it, and while I'm wary of making assumptions (and even mr hank himself seems apologetic), I can't help but be thankful that it wasn't something I said. I was at PyCon, had conversations, and might have even made a joke or two. I don't think I said anything that might have come off offensive to anybody, but given how innocuous this whole thing seems to me, as somebody who admittedly hasn't followed the story, I just can't help but feel some great travesty happened.