It seems to me that a sufficiently cunning arguer can come up with what appears to be a slam-dunk argument for just about anything. As far as I can tell, I follow the arguments in the MWI sequence perfectly, and the conclusion does pretty much follow from the premises. I just don't know if those premises are actually true. Is MWI what you get if you take the Schrodinger equation literally? (Never mind that the basic Schrodinger equation is non-relativistic; I know that there are relativistic formulations of QM.) I can't tell you, because I don't know the underlying math. And, indeed, the "Copenhagen interpretation" seems like patent nonsense, but what about all the others? I don't know enough to answer the question, and I'm not going to bother doing much more research because I just don't really care what the answer is.