Well I was on my 10th day of living on one character, then the change to zed detection and the nerf to prone happened. This patch also had major bugs in it to where zed aggro'd from WAY far away. Also loot was broken for a bit. (funny part about this patch, it's when they changed beginner gear, and I laughed at that thinking I would live forever, whoops) Well I loaded up, did what I was used to when it came to avoiding zeds, well I pulled one and had to fire my DMR to kill it. Pulled all of Stary, died quick. So my guess on the declining life expectancy, which I have noticed as well, is the community getting used to the new zed mechanics, and not spawning with a gun.