dunno. The rationale I read is that the "DA"-style trigger of the Glocks and the XDs - where the striker's only half-cocked or whatever - somehow protects you more than the PPQ's full-cocked striker state. Dunno if I buy that, since it seems to me that, in either case, a trigger pull's resulting in the gun going bang.
Bunch of BS fron fanboys of competing brands IMO.
The Walther P99 AS is the perfect pistol for those that like the PPQ in every regard but don't want the constant action trigger like the PPQ/Glock/XD/M&P. The P99 AS has the antistress trigger option and and the capability to emulate a DA hammer fired pistol and has a decock.