One big issue is that M-theory makes more than one prediction about the nature of the universe. In fact, the number of predictions it makes is somewhere around 10 to the 500th power. That's a 1 followed by 500 zeroes.
"On the surface, that sounds like a bad thing," Krauss said.
Yeah, I'd say that sounds like a bad thing. Many think they have cast off the shackles of superstition and now come to their thoughts through rational, objective science (aka, positivism). Yet, many of those same people believe ideas based on their potential to either explain everything or generate the kind of future they like.
Anyway, it is interesting that many people think understanding the origin or end of the universe is important for humans to know. I have my doubts.