[chongli]

Should the inventor not get rewarded for his work?

The patent isn't a reward for his work, though. The patent is a reward for having an idea and filing for it. The inventor could just as easily spend years in the garage and come up with nothing patent-able, thereby obtaining no reward.

[sliverstorm]

The patent is the opportunity to be rewarded (paid) for your work, instead of ripped off. Sans patent, BigCo just takes your great idea.

[chongli]

Sans patents, BigCos are forced to compete in a commoditized market even more cutthroat than generic drugs (since those are at least regulated by the FDA).