It is my understanding that Rockstar existed prior to Microsoft and others getting involved. They merely footed the bill.
Now, in a fair competition, that should give them an advantage over others who failed to manage their risks. But the way everyone here behaves, people expect them to just let things lie, effectively footing the bill for the rest of the industry. How's that fair?
Well, they (at least many of them -- e.g. Microsoft, Apple, etc) also 'play the game' with their own patents, so it's not out of character for them to use patents offensively. By using their patents offensively, they are contributing to the situation where they are required to 'foot the bill' with their own liabilities, at least. If they adopted a less aggressive stance, and instead put the money they've spent on lawyers towards lobbying for patent reform, what they 'need' to do to limit their liability might be really different.