I've seen that a lot also. A Duke father will give his 0 loyalty son a Count Title, the son then DOW's his father, daddy-dearest annexes said county, son moves back to Court and idiot-daddy gives him a title again, which repeats ad-naseum until one of the two dies while battling each other.
Personally, I put the 0 loyalty squarely on when the kid was a fosterling at a another Court, and he moves home with that same 0 loyalty and daddy immediately gives him a title. I wish loyalty was re-set to 100 when a fosterling moves back home (as it does when a Courtier leaves your court for another court).
Something to wish for for CK2??