I should probably point out that those 13 deaths listed above are over 12 months, not 6. Still not a good statistic though.
As i mentioned before, some of those were also GA aircraft, though they were reported as being ultralights on the news. This sort of thing doesnt really help our image as a safe users of the airspace. I'm pretty sure the RV-4 was GA, and also at least one of the QLD crashes (though i dont remeber which).
Unfortunately this passtime we all love so much does have some associated risks and in some cases no matter how well the pre-flight checks or maintenance has been done something will go wrong. On the other hand doing acrobatics in a non-rated plane probably isnt going to help your chances survival too much.
I'm not sure what the fix is, but I believe unless things start to change soon we are going to lose some of our privileges, which would be a crying shame.
With regard to the "human factors" being discussed above it may be helpful to use the military concept of the OODA loop (see: http://en.wikipedia.org/wiki/OODA_Loop). It is a simplistic way of looking at the decision making cycle used by pretty much everybody - you Observe a problem, you Orient your observation (based on your learning), you Decide how to react, and you Act.
Anyway, its an interesting concept which gets used by the military to help train their pilots in decision making in unusual/emergency situation. They do that by creating unusual and emergency situations for them to deal with.
Maybe incorporating more system failure (i.e radio, electricals, gyros, engine) scenarios into our training would help lower the death toll in the future.