There are 3 problems that make this so:
1. The courts are unpredictable. You can be right and still lose. The cost of losing is typically huge, else the trolls wouldn't have bothered you. So you have to prepare with quality counsel and pay them to do it right.
2. Settlements are entirely predictable.
3. Based on what #1 costs and #2, the troll simply negotiates to settle for less than just appearing in court for #1.
Last time I was at a company that was sued by a troll, counsel said it would cost us $1M to prepare for the first day in court. The troll had a bogus patent that basically said any application that applies business rules to a database infringed--I kid you not. I think we settled for circa $600K.
It sucked and wasted everyone's time like crazy, not to mention the wasted $600K.
Something needs to be done to either eliminate software patents or get rid of this ridiculous asymmetry of costs where trolls are rewarded for playing as many cheap lottery tickets as they can.