He did it to divert investment into high speed trains, which have the potential to significantly reduce the number of Teslas he could hope to sell.
He successfully made investors waste hundreds of millions into these hyperloop startups, which are like real life parody of high-tech scam startups.
On the other hand, one must be quite illiterate scientifically to buy into Musks grand sci-fi projects. Should only work on 5 years old. But you don’t have to believe, you just have to pretend and take these easy millions from rich but dumb VCs.