whoa whoa whoa, intentions definitely matter. Its just that we can't read minds and even sarcasm detection and joke detection tends to fail on the internet.
No, they don't really matter that much. Maybe someone would be content to know that someone "didn't mean it", but as I said before it's also the fact that people don't like being confronted with the knowledge that they are treated as second class citizens by society. So you can have the best intentions imaginable, and it would still make someone feel bad. And it really doesn't help to know that someone considers it good humor to say things that you take offense to.
This kind of reminds me of what the hacks like Sam Harris and Christopher Hitchens used to say, about how the US is far better than Osama Bin Laden because we don't
intend to kill children, and that puts us "in a different moral universe" (actual quote). But the truth is, it doesn't matter when you're a child that's staring at the smoldering remains of his house and family.