You're the one that said Bowie was keen to make copyright disappear, not me. I'm not keen for copyright to disappear, and neither was Bowie. He simply saw that copyright wouldn't jive well with the internet, and rather than try to fight technological progress, he predicted copyright would lose and decided to think of ways artists could sustain themselves without copyright.
But go ahead and make up your own reality with your petty insults.
1. He wasn't keen on having copyright disappear. He just saw that the internet would clash with copyright law, which it did.
2. Releasing your work as "public domain" is not the same as advocating an end of copyright (or reform of copyright law) because even though he was a leader, it wouldn't change the system. He might make a statement that way but nothing would be gained from it.
3. He could claim his work was "public domain" but legally there's no way to do that. All work is covered by copyright whether you want it to be or not. How long would that public domain status hold up 70 years after his death?
Nobody ever told the tobacco executives their products were changing the world and making it a better place. These guys must feel like humanity is looking to them to solve all the world's problems - although this guy seems like a low rent salesman who listens to rock and roll too loud and thinks he's sticking it to the man.
The idea behind the article is that shifting the burden of policing copyright to the online services rather than the copyright holders will make starting a new service so onerous that few people will even try. You could only do it if you dealt directly with the major copyright holders (which is just a handful of companies in the world). Companies will go from "post anything and make the copyright holder take it down" to "we only post things that copyright holders approve of." There will be fewer options for artists to release their work, and the few options that are available could easily dominate the market.
This might mean that for an artist to release something, they'll be forced to hand their copyright over to one of these entrenched companies for the privilege since they control the limited distribution options, just like before the internet came along. Your indie filmmaker would only be able to get their film released by selling it to a major distributor. This is exactly what middle-man companies want - to be the only players in the game - and that sounds pretty anti-artist to me.
The music business abandoned DRM a decade ago. The music you download from iTunes and Amazon is DRM free, and yet iTunes and Amazon thrives as a business and most of that music is still under copyright. They don't need DRM to run their business.
And not all DRM is bad. Netflix uses DRM, and aside from hindering Linux users it's worked out fine for them. DRM's only bad when it gets in the way of something a legitimate customer is trying to do. In this case, simply watch a movie they bought on incompatible equipment. The only thing illegal going on is breaking the DRM, which is why DRM is wrong here, and having a law against breaking DRM is wrong.