I could just as easily say "free-riding off somebody else's ingenuity is fundamentally unfair".
> ... but it is provably false in Software.
Citation needed? Many of the sources cited in OP have flaws and/or have been refuted elsewhere, especially studies by Bessen & co. Many of their other sources are from people who don't know the first thing about patents. They cite that "This American Life" episode where the clueless dude from M-CAM suggested there's a patent on toast, something that you'd know is BS with a glance at the actual claim and 5 minutes of research on Google.
On the other hand, there are studies showing that having patents increases the chances of software startups get VC funding and successful exits by a factor of four. How much innovation happens without funding? Even the majority of open source is financed by various industry sources.
> When has something (in software) been invented by building on some text in a patent filing?
And how often is something in software not been built by simply copying somebody else's ideas? Some ideas are harder to generate (e.g. RSA) than others (e.g. online pet store) and deserve protection.