Absolutely as a moat, that's what makes them valuable. The point is that the moat becomes a public good once the patent expires. The moats would exist without patents, but there would be less total knowledge and less competition for an indefinite period, rather than a fixed one.
That greed is a motivation for obtaining a patent doesn't make them bad, any more than my decision to care about my wages makes me bad. Greed will exist either way, the question is how best to direct it towards maximising the total good.
> moat becomes a public good once the patent expires
I have heard this argument a lot of times, but I don't see how it applies to software patents in particular. At one of the previous jobs, I was doing some research, and there were lots of useful inputs: conference/journal papers, technical reports, thesises, and so on. The only exception are software patents -- I have never learned anything from them.
In all of them? I doubt it. I can believe that some software patent somewhere have a clever idea that is not described elsewhere -- but I still have to find such patent.
Let's take for exa/mple first google hit for "software patent", which for me is https://patents.google.com/patent/US6353926B1/en "Software update notification".
In my opinion, it is completely useless.
- It has nothing particularly innovative. It describes a specific Windows update mechanism in needless details -- while it is a solid design, most engineers, given the same problem, would come up with similar design. I know I did, and I did not know anything about OSD, CDF or windows update subsystem at all.
- It does not present information clearly. The text is hard to read and needlessly complicated. There are better sources of information about this topic -- I am sure there is a MSDN article and a dozen of blog posts which describe this much better.
- It did not even motivate the inventor! I am almost sure that whatever motivation Microsoft had for promoting Open Software Description standard, it was not to get this patent.
So what good is this patent? As far as I can see, there is no public benefit at all. The only value is for Microsoft, so they can threaten others and stifle competition.
That greed is a motivation for obtaining a patent doesn't make them bad, any more than my decision to care about my wages makes me bad. Greed will exist either way, the question is how best to direct it towards maximising the total good.