I think that it's not necessarily a copyright problem. It's a contracts problem. What I like to see are measures the government takes requiring open access to research, for example, by research funding agencies.
I think there are certain measures that you could take to reinforce the bargaining position of authors vis-à-vis publishers and other intermediaries, but it's not easily done. It's a complex issue. The core point is that it's not a copyright problem. That's the point I was trying to make.