The reason I neck carry is fairly practical:
-My squeeze light would get beat up and be rendered useless if in my regular pocket (based on experience).
-Similarly, my compass would get scratched up by keys, change, etc. Neck wear has kept it in good condition.
-There's a limited capacity to the pockets on my regular pants (not all of my pants have cargo pockets). It's just nice to spread things out a bit.
I've gotten used to neck carrying a few light weight items (compass, Photon light, whistle, and dog tags), so it's no trouble even though I don't normally like
anything around my neck.
The downsides:
-On a hot day when I'm really active, I sweat, and the sweat has gotten into the Photon causing it to activate at a low level even when not squeezed. The only way to turn it off was to let it dry out.
-If not wearing a shirt, the thing can dangle and get in the way.
I get around the sweat issue by buttoning my shirt around the chain just above the carried items such that the chain is under the shirt but the carried items stick out of the shirt. Looks a tad dorky, but in the field I'm not there for a beauty contest. For normal EDC in town, heavy sweat isn't an issue.
I get around the shirtless issue by, um, wearing a shirt.