[dj-wonk]

I'm chucking because you just used "simply" and "unpatentability" in the same sentence. Maybe you can argue your point in a probabilistic sense, but I don't see how you can do so based on the underlying principles. Parallel inventions can certainly still be novel, useful, and non-obvious.

What if we think bigger and better? I can envision a more perfect patent system protecting two (or N) parties who independently invented the same thing. After all, a key justification for patents is to make the up-front R&D cost worthwhile. In the case of parallel invention, it seems more fair to the parties and the public interest to not force N valid inventions to result in either zero or one patents.

[shmerl]

It should be a matter of definition. Since software patents don't deserve to exist altogether, making two parallel invention unpatentable would be only weaker, but still some positive development. I'd argue that this logic should apply across all patent field, not just for software, but for software the benefits are the most apparent.