Just like anyone else, Musk is right some times, wrong at others, and averages out as kind of OK. He's very good at attracting investment though, and SpaceX has been executing really well.
> How come people who hired bunch of grannies to knit a nav computer memory got to moon without loosing a single rocket.
NASA did lose a good couple rockets. They also lost the Apollo I and its crew even before it flew, as well as a number of near misses that were recovered by the brilliance of astronauts (Armstrong saved the day TWICE) and ground crews alike. They also lost two shuttles precisely because they couldn't afford bad news from propagating back to the senate.
> And now loosing 3 rockets and still not orbiting is an amazing achievement?
NASA-style development is very risk averse, which is natural, as it's primarily a government agency tasked with keeping the aerospace and rocket industry happy and healthy, and preventing talented engineers and scientists from moving to Europe, India, Russia, or China. Or North Korea.
NASA can't afford to lose three rockets, because each small piece is expensive and exhaustively simulated and tested before being assembled and launched. It does that to advance our theoretical understanding of how to build spacecraft.
SpaceX iterates quickly and cheaply, blows up engines, rockets, tanks, launch pads and anything else, because it makes them cheaply and use them to learn what NASA does by careful simulation and lab testing.