Give me a single example of a patentable thing in software that is nonobvious and so expensive to develop, that you need patents to protect it, 'less someone copies it the minute you enter market and steal your entire cake.

>a single example of a patentable thing in software that is nonobvious and so expensive to develop, that you need patents to protect it //

Maybe something like http://en.wikipedia.org/wiki/Lempel%E2%80%93Ziv%E2%80%93Welc... or a video codec like H264.

Though personally I think the wording of UK patent law by the letter rules out patenting of such algos (that's always bugged me a little), but you asked.

I think the notion of being expensive to develop is misguided as a test for worth of a patent. Similarly the question of whether it 'needs to be protected' (paraphrasing you).

The question should be does it serve the public to stimulate the free exchanged of ideas in this way; does it promote useful technologies; does it encourage innovation.

[Aside: My preference would be for a shorter patent term to reflect the faster pace of technical change. I'd also bring copyright terms in line with current patent terms as a maximum period.]