In fact, the law as described by Barton in the earlier section of his paper shows that the non-obviousness criterion was deliberately weakened over time, specifically when the Patent Act was passed in 1952 that eliminated a requirement for a "flash of creative genius."
Anyway, I am not a law expert. I am an entrepreneur. My interest is to be able to invent without fear that after I invented and researched and showed that some form of product was viable, some large company (Google, Microsoft, Apple, etc) or a competitor or any other group would then replicate it, claiming to have arrived at the product independently. The bottom line is that it wouldn't foster innovation, it would hinder it. I would have no incentive under the patent system to go to investors and secure funds to do research if in the small chance that the research is fruitful, I will not be able to protect it.
[1] Draft version of Barton's article: http://emlab.berkeley.edu/users/bhhall/ipconf/Barton901.pdf