He is a bit of a loon but some people are blindly throwing money at his projects, no doubt convinced he is the next Steve Jobs. He isn't, Jobs' products were massive hits from the start while Musk's are struggling or they don't yet exist:
SpaceX - regular failures (one yesterday)
Tesla - in the red since its inception
Hyperloop - concept phase
SolarCity - in the red until he bought it from himself
The dreams he has been selling have not materialized yet and I doubt they ever will.
Tesla could work out as could Space X
though I can see some of what you're saying - people are blowing smoke up his arse a bit too much... He did well with paypal and has billions to his name, now he's got the resources to invest in cool things - it isn't like he's the only person to come up with a hyperloop or a self driving car etc.. but he's got the resources to throw at those things.