The short answer may be "yes". Commentary in a recent issue of Greg Aharonian's PATNEWS email newsletter (not on the Web, sorry) highlighted several points that lead one to think we may have brought this on ourselves, at least to some extent.
As I noted a couple weeks ago, there's a significant advantage to doing your patent litigation through a non-producing entity (NPE) in that the NPE is effectively immune from competitor counter-suits. Since they make nothing, they violate no patents themselves. In addition, you can (and here I use the term advisedly) 'rig' the NPE to be little more than a shell, with few or no assets that could be taken in the case of adverse judgment. This is similar to the shell game that corporations (and individuals) often play, separating out assets that could be seized from any legal liabilities - just now it's being applied to patent lawsuits.
In addition, PATNEWS reports, there was a rule change in how one can file a patent suit. In particular, new rules limit the number of defendants that can be named. In one way that's good, because it prevents suit-happy patent holders from sweeping huge brushes around, hoping to catch someone who would rather settle than fight. But in practice what it has meant is that instead of one suit with 10 defendants, NPEs now file ten separate lawsuits. The result is an apparent inflation in the absolute number of lawsuits, but that's something of an illusion.
It's not wholly illusory in that the ten separate suits are a larger burden on the court system - this is why courts often try to consolidate cases where possible - but it does mean that there may not be so large a rise particularly if you compare "number of patent lawsuit defendants" on a year-over-year basis.
Another commenter pointed out that reversals (at appellate level) of district court rulings has risen to nearly 50%. A reversal can come in many forms - sometimes a case is reversed and ended, but more often a reversal means it's going to be appealed further or be remanded back down to the lower level for a new trial. As the number of reversals goes up, the overall count of cases goes up. And of course a retrial may itself result in an appeal, and so on and so on.
Reversal on appeal also complicates matters. Generally speaking it's the trial court's job to find on matters of fact. On appeal, each side more or less has to accept the facts as presented at trial but argues that the law was inappropriately applied or that there was some other procedural error. In effect the arguments on appeal of a standard case tend to be totally different. However, in patent cases, the appeals court can sometimes rule a patent or patent claim invalid. This can force a whole new trial as the losing side now has to make its case with lesser (or at least different) facts available. The result, again, is an apparent increase in the number of patent trials.
None of this is to say that there aren't too many NPEs nor horrid abuses of the court system (as there are horrid abuses of the patent system). But it does point out that people bemoaning the current patent litigation system may need to examine things a little more closely. And because I like being right, I claim this sort of analysis lends weight to my assertion that trying to fix the patent system problems at the court level is too late. We must make fixes upstream, at the application, review, and granting stages.