If Musk was after money, he wouldn't have started SpaceX. A rocket company is the dumbest way to make a fortune that you could imagine, short of putting your money in a pile and lighting it on fire. That he's made it work (so far) is miraculous.
Even if it was VC worthy, throwing all your money into two companies like that, when you're already rich, is not the sort of thing you'd see from someone motivated by money. The whole point of VC investing is to invest a little money in a lot of them to even out the risk.
There is no altruism here, he's trying to create an industry where he would be the monopoly.