For one, I noted socialism as being negative because it has a negative connotation in this image. The fact that it's plastered under the face of a super villain, no matter how awesome the villain, just makes it seem that the creator of this poster does not think positively of it. The basic construction of the image is associating the word socialism, Obama, and villainy all in one picture.
For two, the idea of capitalism isn't for an invisible hand to guide the economy. It's for all the hands of the consumers of the free market to guide the economy. Each individual contributing to the current that decides what fails and what succeeds, as per the demand of the consumer. At it's core, capitalism is not a brilliant method to maintain a healthy economy. It's like everything else in this world, it has it's downsides and upsides. I'm sure we're all familiar with the downsides at this point (such as monopolies and robber barons), but the upside is that we have liberty and choice.
For three, the idea of socialism is not perfect at it's core. I don't care how many socialism-junkies on the internet tell this to me. It's ridiculous that people can acknowledge that not any one aspect of life is in black and white, yet they come to this issue and treat it that way. There is no perfect system, and that is because we are human. Humans, by nature, are imperfect. Thus, our creations, by nature, are imperfect. We have flaws, lots of them. Just as our machines rarely run at 100% efficiency due to kinks in the system such as friction and other things we all learned in science class, the machine that we know as society will never be perfect. We do not have the privilege of living in a perfect world. We just have to make do with what we have.
That all being said, blaming all your hardships on some stereotypical rich capitalist with frivolous purchasing habits is hardly mature. Making up some scapegoat for you to hate because things are going poorly does not help stop things from going poorly. It merely propagates a stereotype for people to hate, and hate never fixes anything.