Leaving aside the desirability of software patents, the "real products" element is not a useful way to define who is a "troll." Economically, one of the functions of the patent system is that it allows specialization and division of labor. It allows you to take the results of R&D efforts and wrap it up into a property right that can be the subject of market transactions. ARM doesn't make CPUs; it sells IP that a wide variety of companies can incorporate into "real products." ARM's expertise is in CPU design. It's economically efficient to let it focus on that, instead of forcing it and every other R&D house to also master manufacturing, supply chain, etc.

(I'd also posit that this is a good thing for consumers because it is a force pushing back against vertical integration. In the long run, I think it'll turn out to be a bad thing for consumers that the market is moving from ARM supplying IP to dozens of manufacturers, to a handful of companies with like Apple and Samsung moving CPU design in-house within a vertically-integrated supply chain.)