The core is my preferred location, it's immersive and I enjoy scavenging on edge, I spend a lot of time there before TC and it's sad not to see any other players running through because that would be so powerful, if you saw another faction member run through it would be so intense. The reason no one is in the core is because of, lack of reason. These lockers are so simple but yet would add reason for people to be in the dangerous Phoenix core, adding spontaneous factional congregation or a coincidental planned attack on you and your locker, the wasteland is a fucked up place and people camping by your locker makes sense in every level of the idea, just picture it. It is both positive and negative, if you don't want campers don't put a locker there, if you want ease of access then you can have a locker.
To combat the lockers everywhere statement, there is an easy fix, you're just thinking too linearly. 1 locker per person in the core, and add other limitations like.
-Must be in a building (there are a lot of buildings in the core)
-Must be against a wall
-Could be hard to place or carry to the location
-Removed from play with (x) days inactive
I think this idea adds more depth to Ashes of Phoenix other than the control over Warmart the Whorehouse and Robco changing hands every hour to no benefit but blind competition. Which is ugly and not what the wasteland is about. It's about survival and that every second could be your last, due to another player finding you. Not you going to look for them and using all ur big gunz 2 kill waki sneaker.
And it is such a simple idea, easily implementable.
+1 from me, if that helps.