I agree. This is explained in detail here: How does KiCad know which symbol pin represents which pad of the footprint?
@heriks
Footprints can not be mirrored as mirroring a hard body is impossible. (A physical thing can only be rotated and translated. Every other operation can only be done on mathematical or virtual things. A footprint is a representation of a physical hard body and therefore limited to the operation possible on them.)
Might it be that your problem is related with this? Indicate on the schematic symbol the physical motion of a potentiometer · Issue #165 · KiCad/kicad-symbols · GitHub