It is a great way to avoid your kids or your wife/girlfriend. Sometimes they'll say things like, "OMG. You're playing that AGAIN? You're obsessed with this silly game!" But you can just ignore them until they leave the room, then go close and lock the door and resume your zombie bashing. They may try to get in later or yell at you through the door but that's why deadbolts and headphones were invented.
Also - playing Project Zomboid can be so time consuming that it actually reduces the number of potential arguments that you can have with your significant other or best buddy, so abandoning friends and family for PZ could have some relationship benefits.
Project Zomboid saved my marriage!