This is one of the best stories I heard. Imagine you have discovered the theory of everything, the TOE. You want to publish it and prove that it is correct. Of course, you need to show that it contains quantum theory, general relativity, quantum field theory, the standard model and so forth. For this proof, you will need at least a hundred pages, maybe much more. But no journal accepts such long papers. No problem, you think, "I'll publish it in pieces". No, that is not possible either, because then the "unsubstantiated" claim of a TOE cannot be made in any of the pieces - except maybe the last one. Then the earlier pieces have no interest and will not get published.
Now we have another reason why no TOE is found in a journal so far.