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
There may be altruism and mission involved, but Tesla isn't (and shouldn't be) a charity.