I still don't think this is as serious a defect as you suggest, but either way it's another example of PSA being unable to call out wacky-specific issues. This kind of thing is really only seen on wacky die cuts, much like off-center die punches. You would really need a wacky-specific grading company to expect any kind of real consistency on wacky-specific issues like these.
I think PSA should have a scoresheet for each grade tied to the serial number of the card & available on the web something like this:
TL Corner: (1 to 10 grade)
TR Corner:
BL Corner:
BR Corner:
Centering: xx% top/bottom
Centering: xx% left/right
Gloss:
Coloring/Eye appeal: (1 to 10 grade)
Left Edge: (1 to 10 grade)
Right Edge:
Top Edge:
Bottom Edge:
Clean Back:
Kinks: (1 to 10 grade)
Orientation: (sometimes the card is cut a bit off lever. The card is square, but the wacky is tilted)
Diamond cut/cut out of square:
For centering over xx%, qualifier OC, for centering over the border MC
For gum stains: GS
For other stains or marks, ST or MK
They should also note if the stain is on the front or back. Sometimes a stain on the front can be removed, or a stain on the back may not bother someone, but you can't even see it in the holder.
And give each item a grade on 1 to 10 & weighted average score of overall importance.
This way, people could buy a card with the qualities most important to them, and you'd know how they came up with the grade. Does PSA have any interest in keeping their grading criteria a secret?