Sure, I thought it was pretty funny. But of course, I completely understand the outrage.
The reason why perhaps a lot of us find it funny is because we know it's not true. Michelle Obama isn't a militant African-American woman, but is an incredibly accomplished wife and mother who has experienced racism in the secluded corners of academia (*gasp!*). Barack Obama isn't a terrorist-sympathizer just because he may have spent four years of his young childhood in a predominantly Muslim country. We get it. Ha ha.
I understand that the cartoon intends to prove something along the lines of "you retards really think this is going to happen if Obama is president?" But some people really do feel that the cartoon is an accurate portrayal, and in that sense, the cartoon may give credence to these awful memes. It isn't going to change the minds of people who really think it's true.
But what it will do is allow right-wingers with less than good intentions to further emblazon that image in the minds of American voters. And if they ever get called out for their bullshit, they will only have to wave the cover of the New Yorker and mention how no one was upset when they did it and how we're all a bunch of hypocrites.
The outrage is completely warranted.