I only use the legal definitions because patents are a legal construction. Truth be told I think that most patents and all software patents are bunk and should never have been granted. So, using your definition, I think that all software patent holders are patent trolls, at which point the name becomes meaningless. No one is better than another.

Most people say troll to mean someone that owns a patent that didn't invent it. That is the definition that I object to since I don't think they are any worse than other patent holders.

From a strictly moral sense, patents are at best neutral and, more often, entirely immoral when you consider how patents prevent as much or more innovation than they were supposed to encourage. Patents are supposed to help society by encouraging invention and innovation, but that assumes that the innovation would not happen without patents. To me this means that patents should only exist if they describe something that would not exist if not for patents. I challenge anyone to find a software patent that describes a useful invention that was only developed because of patent protection. All of the patents I have seen created or heard about, I'm not supposed to go looking for them, describe ideas that were developed during the development of a product and only patented when a layer realized that they could describe them in a novel way. Perhaps software companies rely on the patents to help pay the salaries of those developing products, but at best this means that they have more money to pay the programmer that developed it.

Amazon "invented" one click purchasing not because of some r&d department working in a vacuum, but because they wanted to speed up their customer purchase process. That was going to be done with or without patents.

Some inventions are done by researchers at universities, but again, they would work toward inventing thing without patents too.