It isn't unsafe to carry. It does have the same weight trigger as a stock Glock. If you can safely carry a Glock, you can safely carry a PPQ. It is not safe to carry a pistol that has a trigger so light that you might unintentionally fire the pistol. I don't see how the 5-6lb PPQ trigger with the safety on the trigger warrants that caution.
Rifles: Custom AR-15, Tavor, Arsenal SGL 31-68
Handguns: Colt Python, XD(M) 4.5" .40, Glock 19, M&P 9mm, Walther PPQ 9mm, FN FNS-9, HK P30S 9mm, Walther PPS 9mm, Browning Buck Mark