The recent trend in patent litigation reminds me of what happened to the insurance defense litigation back in the days.  

Decades ago, insurance companies settled personal injury claims (for example, personal injury claims from auto accidents) without much fight.  Unscrupulous lawyers took notice of that and started making false and meritless claims (with the cooperation from unscrupulous doctors providing fabricated or inflated medical bills) in order to get settlement out of insurance companies.  It essentially created an industry for this.  When the problem got bad enough, insurance companies fought back and started scrutinizing every claim and litigating dubious claims. 

Patent litigation seems to follow the same path.  Patent trolls sue companies with unreasonable and meritless patent infringement claims.  In the face of high litigation costs, many companies chose to settle even though they knew they had a great chance of winning in court.  Now the tide seems to have turned.  Many companies are taking dubious patent infringement claims head on (though some companies still settle out early for "business reasons" (e.g., need a presentable balance sheet to protect stock prices)).  I personally like the trend of fighting for principle.  After all, I believe in fighting for the truth, not just money.