over 4 years ago - Shurenai - Direct link
It's possible to design something for an intended purpose, and have it be usable in other unintended ways that may not have been thought of during the design process. For example, the first person who made a knife out of a stone or a bone probably did so for hunting purposes- I doubt they ever considered the knife would end up being used in murders for millenia to come while they were making that knife in the first place.

They added flat barbed wire because it was a cool thing- But players found a way of using it in a way that was unintended; a way that made the barbed wire never take damage and so be able to slow zombies without any resource cost.

The intent was for the barbed wire to slow enemies in return for durability that must be repaired/replaced. It was designed with that intention in mine, it was given a hitbox that matched it's shape. For what it was intended to do, it does flawlessly. But because the hitbox can be hidden in a way that never lets a zombie touch it. However, the scan box for the slow is the entire cuboid region of space the barbed wire occupies, and this is hard coded in the engine- if the cube is to have an effect, it affects the whole space.

This same difference in shapes is the reason log spikes also were removed from player access- Because the whole block has the effect of damage, any part of the block deals damage...even the bottom. The spike was disigned with being pointed up, or outward...but it wasn't considered that it could be placed upside down as well.

Edit: To add, It's not about 'winning against the players'; The devs could do that hands down and make the game absolutely unplayable with very little effort. It IS however about making things work the way they are intended to.