A new super-fast sorting algorithm (not just a few cycles, but something that actually changes the O-number) would obviously be a fantastic boon - I would want the inventor to benefit from his cleverness.

But nowadays I think patent law isn't the right way to do that; trade secrets should be enough. I don't think that what is disclosed to the public in patent applications is of enough value to justify a long monopoly. It's not necessarily a problem with the written law; patents are horrible because of the way courts apply them.