Because patents are not intended for mathematical principles or business processes, and that's essentially all software really is. Applying mathematical principles to the implementation of business processes and calling it "business logic" shouldn't magically create a new legal status.
The software implementation of mpeg2 is covered under copyright.
The math/algorithms/whatever are covered by patents.
I could write a totally distinct implementation of mpeg2 called "myvideoencoder" which used the same math, and the patent would make that a violation of their rights.
Math isn't patentable per numerous rulings in the past, but somehow once a computer is doing math really fast it becomes patentable.
What's being patented isn't the math, it's the implementation of that math.
As a counterpoint that argues why software patents should exist, I'll point out this. If you build a mechanical feedback mechanism that acts as a controller for some chemical process, no one doubts that said controller meets the patentability criteria. So why should we penalize inventors for emulating that controller in software instead of doing it in hardware? (Note: this scenario is effectively the one that established the patentability of software).
The real problem is that the bar for novelty and obviousness in software ought to be much, much higher, and software, having shorter development cadence, needs shorter patent protection times. The most useful change to patent law would be to have patent times adjust to reflect typical development cadences, as opposed to being fixed across all fields.
>What's being patented isn't the math, it's the implementation of that math.
That makes absolutely zero sense as an argument.
It is absolutely the mathematical principles being patented otherwise how can you possibly prosecute anyone of an independently implemented implementation of the maths?
I think the backlash against existing software patents and how they're used is why people take such a hard line against software patents.
I don't have anything against software patents per se, and your example, I think, is a good one, but 20 years in a field moving as fast as software is ridiculous (I'd push for 5 years at most), and the ability to be issued a patent on trivial bullshit is insane.
I was thinking 3 years, but the USPTO would probably have a tough time actually granting the patent that quickly.
But, yes: the current system is undoubtedly broken. Terms are way to long (for software, at least), and too many patents are clearly violating the novelty bar.
That's a bit of a jump. You go from "mechanical systems are patentable" + "some software emulates mechanical systems (which are patentable)" to "all software, regardless of whether it is related to a real mechanical system, is patentable".
Does that not seem like a huge leap? mpeg2 sure isn't encoding a mechanical mechanism. Hardly any software these days really is. Software now is mostly focussed on dealing with ætherial information, not physical machines.