Where has it been stated (except by a few Detractors™) that JB believes that every mistake he ever made is somebody else's fault?
Paul is attempting to move the goalposts; a logical fallacy.
This conversation has not been about every mistake Byrne has ever made. It's been about every book Byrne has ever quit prematurely. And as far as that goes...
X-Men: Byrne blames Claremont.
Fantastic Four: Byrne blames increased editorial interference
Superman: Byrne blames Dick Giordano
Next Men: Byrne blames the comics market
Danger Unlimited: Byrne blames retailers
Avengers West Coast: Byrne blames "a bone-head EiC who did not pay attention."
Captain America: Byrne blames Jim Shooter
Hulk: Byrne blames the Editor in Chief.
Indiana Jones: Byrne blames Jim Shooter and LucasFilm.
She-Hulk: Byrne blames Bobbie Chase.
X-Men (second run): Byrne blames Jim Lee.
This is all from Byrne's FAQ. These are his stated reasons.