For instance, determining the optimum layout of a mail application for a four inch screen probably takes a lot of tweaking and user testing. But there's no way that you can call it an invention, and your competitors are free to copy the layout, so long as they change the style enough that customers can clearly distinguish the products.
On the other hand, using a magnet to hold a power connector to a laptop seems like a really obvious idea once you've seen it. You don't have to study detailed documents to see how you could make it. But calling it an 'invention' seems reasonable - and it is patented. And it's perhaps the only thing that attracts me about Apple laptops, but that's not important right now.
That may have merited a patent (if it wasn't already invented, and I suspect it was), but Apple's implementation does not.
I get that it's difficult to incentivize the development of truly difficult abstract ideas, but mathematicians and physicists have been doing exactly that for centuries and they appear to be doing alright.
So I was an aerospace engineering major in undergrad. For my professors, financial support came from: 1) government; 2) tuition and fees from students looking to get jobs at Lockheed, Honeywell, Raytheon, etc.
The former is mostly subsidized by the military, while the latter is subsidized directly and indirectly by companies who definitely do leverage patents and trade secrets laws to monetize their developments.
So its a "pick your poison" situation.
Screen rotation is no invention. It's an idea; once you have it, it's trivial to implement. That, IMO, does not afford patent protection. However, certain things can, and should be patents. RSA, for example. It's a non-trivial procedure that was non-trivial to invent and there are not very many alternatives.