Software Patents are not that harmful!
A patent blog post: Have Patents Killed the Software Industry in the U.S.? Hardly.
In the early 90's, the software industry in the U.S. decried the rise of software patents, claiming that patenting would doom small companies and stifle growth in the industry. ... Anti-patent activists, particularly in the EU, have used many of these comments as fodder for their quest to eliminate software patents altogether. They have even gone a step further in their rhetoric, suggesting that it will be impossible for software companies to operate once software patents are recognized, since larger sompanies will swamp the smaller sompanies with patent filings and litigation.
However, a current study being conducted by Robert P. Merges, demonstrates that this viewpoint is mostly wrong — patents have not killed the software industry, they have not led to a slowdown in entry, and they appear to have had a negligible impact, if any, on industry structure.
Wow, what a strong argument for patents: they have not harmed the software industry that much. Of course, this does not imply the patent system has no costs; or that the costs are exceeded (somehow) by the benefits of the system (in fact if it has no effect, that means it has no benefits, right?). For more on this, see There's No Such Thing as a Free Patent.