re: Better Idea
You'd still need more than one license anyway, depending on what you were allowed to do with the source once you had it. Verify and run, modify for private use, modify and provide the modifications to the community, modify for commercial gain, extend but not modify, extend for commercial gain, each varient would require a different license, and would be governed by different laws. You'd also have to seriously rewrite copyright and patent law, not to mention trade secret protection law, which would require years, millions of pounds and international cooperation.
I'm trying to think of another thing that someone could buy and reasonably demand full access to the thousands of hours of work that went into it so they could make sure it worked, or make changes because it's not quite to their liking, and I can't think of one. Go to a resturant and insist on watching the food being cooked so you could change the seasoning if you think you can do better? Watch your car being built, so you can pick the nuts and bolts yourself? Buy a book and change the ending so it comes out the way you want? You could do all these things, but if you have the skills needed to do it well, you also have the skills to do it from scratch, exactly to your liking. It might take a while, but then it took the original developers a while as well.
Personally, I have never sold or supplied a single copy of any piece of software I have written. I sell access to my software, which runs on machines I own and control. My clients have no need to see, and would have no idea what to do with, the source to the applications they use. All they need it to know how the interface works, what the business logic is behind the application, and the data model that backs up the logic. This is why they hired me in the first place. And if they are interested, and were prepared to spend some more money, I might let them know the details of the API, so they could build their own interface.
This is the future. And also the past. It's only the present model that's flawed, where users think they own the software they paid to use.