I agree that artists should only make their albums available on streaming services after a month or two to encourage album sales. But the artists who don't ever make their music available for streaming annoy the hell out of me. Not all services pay as little as Spotify (Simfy pays significantly more per stream for example) and records aren't even a primary source of income for the vast majority of artists.
Streaming services also make it very easy to discover new music (my music world has expanded exponentially since joining Simfy), which puts me on the lookout for upcoming albums and live performances. I read a few months ago that the average monthly cost of a music streaming service exceeds the average monthly spend on music of iTunes users. Labels need to improve the deals in place, because the problem isn't the money coming in.
Perhaps the artists are butthurt because the streaming model punishes bad music brutally - an album that is streamed many times over a period of years will generate more than $10, but one that is skipped through and forgotten will get as near as nothing. It's also worth bearing in mind that it's not fair to directly compare DRM-free sales with stream counts. Streams occur MUCH more easily than album sales as there is no additional cost to the user, so it is folly to suggest that all those who checked out an album would have otherwise bought it. And streams cannot result in copyright infringement because the user does not own them and cannot distribute them.
Imo, streaming is the future of music. You get access to everything at a set price, you can have a ginormous library whilst only keeping the most relevant selection stored locally, all your devices can access all the music, your playlists are always in sync across devices, piracy is of no concern, more money is brought in from listeners etc. It's music nirvana.