IIRC, there's an Islamic belief that only Allah makes things perfect, & if a person tries to make a perfect Persian Rug (e.g.), it is an offense to Allah, borne of Pride.
The #SwedishBaptist version of essentially this same sentiment is why my mother puts Walnut chunks in #ChocolateChipCookies
They can't be completely delicious - they need to be at least a little bit nasty & gross.