I don't know how much this kind of patent warfare happens outside software. It's only in software that you can count on competitors "infringing" your "inventions" if you simply buy enough patents.
For example I could imagine car manufacturers all having a bunch of patents... just imagine. Nissan have a patent on controlling your car radio from buttons on the steering wheel. Ford have a patent for having the horn button on a stick that's connected to the wheel, while VW have a similar one for the horn button right on the wheel itself.. Could go on and on, and they could have great fun taking each other to court.
Some industries maybe aren't so open to pointless patents (maybe pharmaceuticals?), but in most I think you could do a hell of a lot. Maybe they already do the same, but we just don't hear about it. Maybe they could, but are wise enough not to bother. Maybe the patents system has just been in use for a longer time in those industries, so companies aren't allowed to get away with so much crap?
Some interesting bits from that Wikipedia page, which demonstrate that patents don't necessarily promote innovation and that being too litigious with them can damage one's reputation:
From the "Patent War" section:
"The Wrights' preoccupation with the legal issue hindered their development of new aircraft designs, and by 1911 Wright aircraft were inferior to those made by other firms in Europe.[9] Indeed, aviation development in the US was suppressed to such an extent that when the U.S. entered World War I no acceptable American-designed aircraft were available, and the U.S. forces were compelled to use French machines."
From the "Aftermath" section:
"The lawsuits damaged the public image of the Wright brothers, who were generally regarded before this as heroes. Critics said the brothers actions may have retarded the development of aviation,[9][14] and compared their actions unfavorably to European inventors, who worked more openly."
"The Sewing Machine War was the first instance of what is today called a 'patent thicket.' The disputes prevented Singer from selling his invention, and tensions ran high in and out of court: When Howe personally called on Singer, Singer threatened to throw him down a flight of stairs.
But there’s a happy ending to the story, as your machine-stitched clothes evince. The Sewing Machine War ended with a just and lasting peace in 1856, when Orlando B. Potter--a lawyer representing one of the plaintiffs--suggested a solution that Mossoff calls 'groundbreaking but also breathtakingly simple': The patent-holders would combine their patents in a 'patent pool' and share the profits from selling the machines. The patent pool participants lived happily and wealthily ever after--or at least until 1877, when the last patent expired."
"Contrary to theoretical predictions, the sewing machine pool appears to have discouraged patenting and innovation, in particular for the members of the pool. Data on stitches per minute, as an objectively quantifiable measure of performance, confirm these findings. Innovation for both members and outside firms slowed as soon as the pool had been established and resumed only after it had dissolved. "
The same problem occurred during the invention of the sewing machine, and the patent holders actually got together and formed a large patent pool, enabling them all to profit and innovate while still protecting their work.
The auto industry does enforce their intellectual property. Toyota and Denso are very serious about enforcing the IP on their hybrid drivetrain. Ford and Nissan license the tech, and no one else has developed a CVT + continuously variable assist hybrid setup like Denso/Toyota.
I don't think the auto industry would ever take each other to court over trivial patents, for the same reason Microsoft /Apple/IBM don't go to war. If Tesla does make billions in profits, I think the we will see "horn on stick" and "button on steering wheel" patents being enforced.
With software, you can design, build and sell a product overnight for virtually no cost and do the same.