My conclusions regarding this are:
a) only a small portion of all STI owners are on NASIOC or IWSTI so we are most likely blowing this problem out of proportion.
b) There's certainly a weakness in some STI engines and they will blow up regardless of the tune. But all car makers have occasional quality failulres on some units.
c) crappy drivers/bad tunes/mods
are most likely the primary cause of this.
How many floor their cars in 6th gear going 60 mph?
How many are aware of CL/OL and boost creep (especially in cold weather)?
How many enjoy bouncing off the rev-limiter or using FFS and LC in excess?
How many drive their cars hard cold?
How many maintain their car according to Subaru guidelines (ex.: people who use the same oil in ALL their cars and disregard Subaru requirements).
How many beat their cars in general? No one buys this car to drive it slowly...
The list goes on...
I would not have any problems buying a STI, I would keep it stock for a year (15-20k miles) and if nothing breakes, start modding intelligently thereafter.