I'm guessing Spotify is losing money because it has a very high cost base and it spends a lot on marketing to try to get new users. It could make money if it choses to decrease how much it spends on marketing, but it's growth will probably slow down by a lot, or maybe even decrease as current users start leaving.
I doubt apple makes money on its music streaming service either if it takes into account ALL the costs associated with running it. It probably doesn't because the music service uses a lot of the infrastructure, employees that are used in other areas at Apple, and it makes money selling music, which subsidizes the streaming service.
I could see the reason why it would make sense for Spotify to purchase Soundcloud, just like how Amazon keeps purchasing smaller e-tailers. Spotify can integrate soundcloud "premium" into it's current subscription service, and that'll make it more attractive for subscribers and easier for it to get new users. It probably doesn't make sense for it to shut down soundcloud's free service because it'll get a lot of backlash, but who knows.