In reality, that also helps. He cannot promise a battery with infinite capacity. Cars running on gas need refueling too and sometimes, when I'm running low, I wouldn't mind knowing where the closest gas station is.
Not saying Tesla and Elon Musk will solve the world's problems, but they are trying to solve one or two while still making some profit. What do companies Exxonmobil or Chevron do for us? Really? Endless wars for oil, oil spills and other environmental impacts, price fluctuations and possibly many other negative factors.