This makes a certain sense. Coming up with a solution for other people's problems usually seems easier than solutions to our own problems, but I don't think that is necessarily because our thinking is more "innovative" when we're "removed" from the problem. Rather, I think that we're simply more willing to accept any cost or discomfort that might be incurred when we ourselves are not paying the cost or experiencing the discomfort.
Even in the problem used in the above-mentioned study, it is somewhat easy to see why it was easier to solve the problem for someone else. The "problem" the subjects had to solve was being trapped in a tower with a length of rope not long enough to reach the bottom. The "solution" to the problem was to divide the rope length-wise and then tie the ends together so that they reach the bottom of the tower. Essentially, doubling the rope's length while cutting its thickness in half. Well no wonder people had an easier time suggesting this for someone else! Who wants to climb a skinny rope that might snap out of a tall tower? Of course it's easier to possibly send a stranger plunging to their death than to think about doing so yourself!
Social psychology write-ups (it's really not a "study") like this one illustrate perfectly the unique nature of so much of psychology: studying interesting things in order to postulate imaginary theories really doesn't contribute much to science, on the other hand, these types of write-ups can stimulate thought that might lead to a study that actually tells us something concrete about ourselves.
Think, reconsider, reimagine, and research. Ah, the soft sciences.