Yes, of course, streaming music currently makes much less money for the content owners and rights holders than downloading does - but the key to making this work is to get EVERYONE involved in streaming legally via one of the existing or future services and platforms, just like radio, i.e. starting with a more or less free / feels-like-free or freemium offering. The math is simple: if 200 Million people use Spotify or Simfy or Rdio - whether they pay ‘with attention’ aka advertising, via telco bundles, or with their own cash - then the rightsholders will see some serious money coming their way. If they can’t allow this market to grow, then it won’t be created (at least not in a legal way)
The bottom line is: the music industry has to monetize AROUND the music, not just WITH the music. Think advertising, bundling, added values… new generatives. There is no sense whatsoever in fighting the obvious trend of access replacing ownership.