All I know is my watanabe yanagi and shig deba don't have the problems mentioned here. A real handmade custom is probably subject to stricter QC than a manufactured piece. I'm willing to bet that the variances of each knife depends on the quality standards and acceptable levels of imperfection for each manufacturer/brand.
A minor issue is when it takes more than 1 whack to sever a chickens head.
A defect is when it breaks in half after preparing a salad on my stainless steel cutting board.
Wabi-sabi is when it comes without a handle, or a tang.