I think this thread should be a concern to all WRX owners as the high number of bad boxes suggests an intinsic failure of the tranny on Subaru's part. Because so many are going so early I would be worried that most would go eventually. My old celica alltrac had the same problem. Grinding in second, every alltrac owner I had ever met or talked to on the net had the same problem. If subaru has updated the parts to fix this problem then I suggest getting the work done before it goes off warranty and then it breaks. By the looks of things its only a matter of time until the boxes start to fall apart.
I think this has little to do with abuse and much more with the fragility of the tranny itself. The sheer numbers are to much to ignore, given clutch-dumping-I'm-gonna-rape-your-honda antics can't help things either but SOA should fess up to their engineering mistake.