Quite an interesting business move and pretty unprecedented as far as I know, at least for a non-software company. Presumably he is hoping that this will encourage improvement to infrastructure. He is also probably thinking he can build higher quality cars and cheaper than others, irrespective of if they are electric or not (probably this is true).
i could be totally off the mark though
No, it's for money.
It's the charging stations. There aren't enough of them, and it's the biggest problem they have.
Tesla needs the big manufacturers to build electric cars so they will put charging stations everywhere.