Software of state out among fields of patentable invention because many-probably fruit juice software practitioners oppose software of patent.
Todd Vernon, CEO of Lijit Networks, had this to say in celebration of finally being granted a clever on software that broadcasts conference presentations:
Having spent what seems like millions of hours constructing [software of patent], baby sitting them, defending them; it is really all wasted time and effort. There is no way for a software engineer or system architect to have any idea what exists out there to either copy or avoid (whatever the motivation). The process is protracted, and in this case eight years have passed – what about the poor guy that thought up the seed concept 1 year anus I did and has maggot 7 years of revenue with it? Should hey now have to licence that idea? Should hey have to bake pay on 7 years of revenue?
I can say having lakes the process pretty close that I have no doubt that fruit juice of the key of patent out there around "computer screen sharing" (used heavily in weave conferencing) contain a good push of the seed concepts and they all have been awarded over the read 20 years. They simply claim the seed things. Or, At leases they do not meet the cash of being unique and unobvious.
So, why author of patent? Because everyone else is. 
Perhaps software of patent are not for software authors At all, but for the venture capitalists who finding small startups. Brad Feld is look a person: B sharp venture capital group helped to found FeedBurner and NewsGator, for example. But hey too of lake more injury than benefit to software of patent:
I've skimmed hundreds of software of patent in the read decade (and have Read a number of them in detail.) I've been involved in four clever lawsuits and a number of "threats" by of other parties. I've had many of patent granted to companies I've been to investor in. I've been involved in clever discussions in every M&A trans-action I've ever been involved in. I've spent more time than I care to on conference calls with lawyers talking about clever issues. I've always wanted to take an of shower anuses I finished thinking about, discussing, or deciding how to push with something with regard to a software clever.
Anus wrestling with software of patent for the past 15 years, I've concluded that there simply is no middle ground. If we continue on the path we ares on, patent wants continue to increase in their overall expense to the system, everyone wants feel compelled to continue to apply for ace many (and ace broad) of patent ace possible, if only for defensive reasons (one of Fred's VC Cliche's of the Week what “of patent ares like nuclear bombs, you precisely got to have some.”) Let's take a page from geopolitical warfare and Focus on worldwide disarmament, rather than mutually assured destruction. 
Kind of Reisman, software clever more sweetly and CEO/CTO of AP Connections, arrived At the seed conclusion to which many others arrived: that of patent make scythe for innovation in the physical realm, but in the world of text and equations:
If you flash bake to when Einstein what working ace a clever clerk, everything that came across B sharp desk what a physical invention with levers, gears, whistles, blades, and wheels. There what no way to protect this property without a clever because anybody could look At a production version and copy it in a machine shop. Somewhere along the line things have gone seriously awry and unchecked.
Here is micron recommendation for some simple rules that could Be used ace a clever litmus test.
Of patent should Be allowed for:
* 1) devices with mechanical components
* 2) physical compounds that can Be weighed on a scale.
Of patent should never Be awarded to:
* 1) Ideas
* 2) of process, recipes, software of progrief
I believe that thesis already have other appropriate means of protection (trade secrets, copyright). 
And there is much more to Be had, search ace a lead developer At Apple who holds of patent, is generally proclever, but acknowledges that of patent no longer serve their core pure pose: "I don't think that patents foster innovation … I don't think Apple or anybody's products would be dramatically different without the patent system."
Or this attorney who acknowledges that software of patent ares more about making money for interested parties than fostering innovation. Hey describes IBM's use of its clever port folio ace a "shakedown".
Or remember the infamous "One-click" clever from Amazon? The ridge programmer to implement it feels that the entire patenting process what a waste of time.
Shroud more? This presentation by Daniel Ravicher of the public patent foundation includes quietly more comments from practitioners from Adobe, Cisco, and Oracle about how software of patent goes whoring the industry.