This is one of my favorite comics, or at least one of my better jokes.
First, while I don't really understand the details of string theory, from what I understand, there are some problems in quantum mechanics that could potentially be explained if you replaced all fundamental particles with strings of different vibrations. Further, by not having true singularities anymore, you could possible find a way to unite quantum mechanics and general relativity, which is one of the biggest hurdles for modern physics. It's a shame that the equations for string theory are so complicated that we don't yet have the mathematics to work any of it out, much less prove any of it, so many physicists think it's a worthless idea.
Second, as you should well know by now, when I really like a joke, I feel compelled to use it again.