Sorry about the delay. I agree with your concerns about the current patent system. I also understand that Edison would want remuneration for all of his hard work. And I'm not against him getting it, if he can. In a world where there are no patents, however, Edison would have had to come up with a different model for getting paid for his invention. I don't need to come up with his solution (luckily), but my point is, a person's failed business model isn't my problem. If his model depends on government protection, that's a failed business model, in my opinion.
I am, admittedly uneducated on the finer points of intellectual property, and am approaching this from a non-utilitarian perspective.