Let's go to the math: suppose that Apple's free trial woos 25M (million) to take the trial and Apple wanted to make everyone happy by offering a free trial AND paying for the trial in the background (much like Netflix pays for the content to offer it at $8). 25M times $10/month = $250M/month. 3 month of free trials = $750M. Is that a lot of money? Is that a lot of money for Apple? How much did Apple pay for Beats? How much profit did Apple make just for the last quarter?
Let's make the free trial much more successful: 100M free trial users for 3 months. 100M times $10/month = $1B (Billion) per month times 3 months = $3B. How much did Apple pay for Beats? How much profit did Apple make just for the last quarter?
And that's not even the real math, as it's including the amount that Apple would be keeping for itself (apparently about 28% or so). Redone: 100M times about $7.20/month = $720M times 3 months = about $2.2B for 3 months. Is $2.2B a lot of money for Apple?
In short, for a relatively tiny portion of the Apple cash hoard (smaller than they paid for Beats), they could just pay the full price of the service for everyone interested in the trial, and it would be almost nothing to Apple. Content creators would get paid, Apple could write it off as a business expense, consumers could try it for 3 months for free.
Furthermore, Apple could get creative and inject some iAds to help pay for the trial and clearly convey that these ads run only for that purpose and would not be included after the free trial ends. This weekend, HBO & Cinemax are running one their free trial weekends. These (what are usually thought of as) commercial-free channels are basically running commercials pitching watchers to sign up for HBO & Cinemax before the free trial ends. Apple could follow that well-established, well-proven lead too to further reduce their own bill during this trial period. HBO & Cinemax are not getting to run movies for free during this period; they are just eating the bill of running the movies as a marketing expense to try to woo more subscribers. Apple could copy this and everyone would be happy.
Instead, Apple, no longer the small, fledgling company it once was... now billed as "the biggest company in the world" or "the most profitable company in the world" or "the most successful company in the world" needs those artists to donate their wares for 3 months so that Apple can try to make even more money. I wonder if, instead of Apple, this thread was about Google or Samsung or Microsoft, would our collective sentiment be so overwhelmingly in favor of those corporations vs. the artists who create the content. (rhetorical)