This is where we get into philosophical differences, as there are issues with "generously wide shoulders" and non-separated bike lanes that the non-cycling public is largely unaware of, the least of which is that it moves cyclists away from your primary field of vision, invites right-hooks, etc.
A more effective solution, in my opinion, would be the better education of both groups so each knows what is expected of them, and what the rights and responsibilities of the other are. I honestly believe this is the source of a lot of angst and accidents between the two groups. Take SpatialAwareness for example, who has a pretty evident vendetta against cyclists. Despite his interest in the subject, he's shown a gross lack of understanding in what the laws are, what's expected of him in various scenarios, and what rights a cyclist has on "his roads." On the other hand, we do have cyclists who think they get all the advantages of the road without having to play by any of the rules. This is the heart of the problem in my opinion.
It's like what happens when roundabouts are first introduced to a city
Now truth be told, I don't ride in many of the conditions discussed in this thread. I don't commute by bike. I don't ride in high traffic areas. I don't ride up mountainsides with precarious rock formations. I'm not willing to put myself in those situations. But I do believe in deferring to the law when it comes to the coexistence of motorists and cyclists.