Musk has two projects for every area of his interests. One is real and one is publicity stunt. Hyperloop is stunt for boring company (cheap tunnels), Mars is stunt for his rockets (cheap LEO flights), self driving car is stunt for his giga factory (cheap battery). If the stunt never reach it's goal it doesn't matter because real goal was to promote real project.
I feel like you're misinterpreting musks motives. Sure he's somehow brilliant at marketing, but I also believe he really wants to go to mars.