[phicoh]

In my opinion that's not what patents are about. Patents are about how to do something. The obvious purpose is that revealing your patent advances the state of the art.

Otherwise, why would the community grant a relatively long term (about 20 years) of monopoly? It doesn't make sense to do that just for a clever business idea.

[three14]

I basically agree with you. The counterargument says that some innovation simply doesn't happen for centuries, until it finally occurs to someone. You want to incentivize those kinds of innovations as well, to get people to revisit old issues. For example, the stirrup. Evident once you see it, but a big innovation, or it would have shown up centuries earlier.