What does the scientific community think of Michio Kaku?

I know he's a theoretical physicist and all, but it seems like half the stuff that comes out of his mouth that he tries to convince people is true is either unproven, not widely-believed by most scientists, overly-optimistic, unrealistic, or just flat-out wrong. For example, wormholes (which require ripping the space-time continuum, which is impossible), warp drives (which require negative matter, another impossibility), light sabers, and other sci-fi technologies that most scientist believe are just that, fiction. Yet he makes them out to be completely true, even when they are not. He's like the conspiracy theorist of science.