Target arguments x, y, z ignored

When using the target arguments @e[x=X,y=Y,z=Z] they are completely ignored and counts everyone as if they had these coordinates.
While testing further I found that any other argument as dx, type, name, tag, etc. works totally fine except for these one.

What I expected to happen was:
When I used /testfor @e[y=100,type=!Player] it would detect all entities other than players at the height y=100

What actually happened was:
Even tough it didn't count players, it would count every entity no matter what their height was.

Steps to reproduce:
1.Open a new world
2.Place a command block with the command /testfor @e[y=100,type=!Player]
3.Summon some entities if needed
4.Power the command block