Please someone explain: New to DayZ and I keep dying to crouching ninjas.

Most of the time I don’t see these players until I’m round a corner or opening a door to get shot in the face. Other times I see indicators of player presence (doors open, infected spawned from far away etc), but again not the player themselves. Suddenly I open a door, or round a corner, then to death screen before I even see their faces.

Does the average DayZ player just wait, gun pointed at a door, if they think someone is around? I feel like my looting behavior is not that predictable, and I don’t loot every building, but I keep dying this way.

Is there a good counter to this type of ambush? Are yall really just out there peeking every corner and door?