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.
Rifle: SCAR 16S, Custom AR-15
Pistols: Colt Python, Springfield 1911 TRP, XD(M) 4.5" .40, Walther PPQ First Edition 9mm, Glock 19