Idea's are a plenty. It's the correct productization that adds value. So - the correct fairness proposal is that the product development efforts to create a viable first example of a product category don't go to waste.
It's very easy to botch up the execution of a new idea into product. That's why it's not very good idea to trust historical specific examples to proof something does not work - maybe they just botched it. Now, when the first working example hits the market place competing players recognize that the method -in fact - can be implemented and have a bread crumb pathway lead ahead of them for viable product.
Now, the product development effort of competitors to reach market may not be any easier despite the breadcrumbs, but the initial product development had way higher risk because of no breadcrumbs to follow - and thus it's fair they should get higher return of investment for a while.
This is not to say the current implementation of patents is not messed up. It's quite telling that quite a lot of industrialization happened globally because people managed to ignore existing patents and implemented effectively industrial espionage to copy machinery. At least the world economy went ahead in leaps and bounds.
That's for common ideas. "Let's make a Facebook for dogs", "dollar shave club", etc. But those are not patentable in the first place (and if they are in some country, they shouldn't be).
Here we are talking for invention ideas. Which are not plenty, and which often require not just insight that billions couldn't manage to have (the invention of the carriage wheel -- which the pro-Columbian population of the Americas managed to miss, even though they had wheel shaped items for other uses), but also millions in R&D (e.g. to design. build, make efficient to mass produce and test a new kind of plane engine or a more efficient battery).
In a lot of those cases where the invention scratches an itch there's very little "correct productization" needed. If you make a better battery material for example, you just sell it like everybody else sells batteries (plus some marketing for its longer life). Some things literally sell themselves.
So if the vast majority of the work being done is fundamentally different, does it make sense to set policy based on the outliers? The work of the patent office is almost entirely focused on "common ideas".
NB: I don't know the answer to this, just pointing out the difficulty.
But judges and PTO examiners have been getting it wrong so long they don't even know what's right anymore. But the letter of the law is quite clear and the SCOTUS is starting to come down harder on the side of the law, especially since rulings like Bilski.
Generally, I'm against software patents due to their easily abused nature (to the point where I think sacrificing all software patents would be a net benefit), but I find it very hard to argue that the person who came up with that codec shouldn't be able to patent their invention. Yes, it's math at the end of the day, but it's still novel math. Putting existing things together in actually novel ways should be patentable.
Novel math is still abstract, and as such, strictly ineligible. Software is the same, in that it is purely abstract. It will take time for the courts to catch up to reality, but they have trended in that direction.
Whether I agree or not that, as you say, "...novel ways should be patentable." they are, by the letter of the enacting law, ineligible.
That it involves not just some singular "let's do an X" moment, but tons of math, hard work, novel techniques for better compression, faster decoding, etc?
I think you'll find this takes a little more work than "Hey, wouldn't it be great to make audio files smaller?"
Because if anybody else can also "productize" your idea, then it will in all probability be others that will make the money (especially if they are much larger than your company, can market more, have economies of scale, connections with retailers, etc.). So you get no reward at all for your idea, or a vastly diminished one.
People wont buy from you just because you had the original idea.
And of course "keeping it secret" AND selling it is usually not an option at all.