It is extremely well documented that markets are very poor at provisioning public goods.
Stonehenge has paid me on several occasions to make improvements to my CPAN modules and only that. They're not the only company to have done so. I know many other OSS authors who have been in that situation. FOSS is very obviously a public good. How would MySQL, RedHat, and other such companies exist without such a public good?
The point that I keep making over and over that you are ignoring is that the direct benefit to the purchaser (their satellite not getting smashed) is so large that the cost is worth it, regardless of the inability to obtain full payment for the benefits created for others. Yes, this doesn't work in all cases. It works in this case.
As for your evaluation of Buk's solution, I think you're wrong. By your admission, the slightest change in orbit can have great overall effect. So, if you were to approach at an angle of 0.1 degrees relative to the motion, you could probably put the debris into a spiral that, over a month or two, would lead it into the earth's atmosphere. You wouldn't have to have it in a ground-ward trajectory. All you need is one where you either bounce off the atmosphere and leave LEO or you burn up enough to keep it going downward. That glancing blow could be done with a parabolic deflector, kinda like a skater going through a half-pipe. Yeah, it would require exquisite timing and positioning. Sounds like a job for a computer, to me.
My criteria for good software:
- Does it work?
- Can someone else come in, make a change, and be reasonably certain no bugs were introduced?