This one thing that I’ve noticed has always confused me; why does it seem that nearly nobody remembers the crouch button in Infection? Every game, most of the Infected I see are just blindly walking everywhere they go, rushing straight to survivor holdouts and getting farmed horde after horde. Same with Survivors. I hold my breath whenever I’m hiding out in a secure spot where no infected has found me yet, but there’s that one idiot who can’t keep still and keeps walking around constantly. Has everyone forgotten that we are all equipped with motion trackers? With all the uncrouched people running around everywhere, it’s too easy to be able to tell when you are about to be attacked by just looking for approaching blips on your tracker.
Why should Infected bother to crouch? When you crouch and take it slow, as well as utilise pieces of cover nearby, you can use stealth to ambush wandering survivors, or get easy kills at the start of the game as the Alpha when the survivors are still spreading out across the map. For those large survivor groups holding out at secure holdouts, you can also crouch while advancing to the location to remain undetected, then quickly advance inside the space abruptly, jumping and thrusting to the side just as the survivors get a clear view of you. Always seems to work for me.
For the survivors, once you’ve found a good spot to defend, stay crouched! If you are going to walk around the length of the entire room, it is needless to say that some Infected are going to eventually clearly see your presence projected on their trackers, and that’s when’s you’re secret location is compromised 
Has anyone felt similarly to me? I don’t know why this bothers me, but anyways just wanted to state this fact that I’ve observed.