Without defects everyone would be the same, it would be a universe of constant peace or a universe of constant hate with or without opinions or rights(along with everything els, ex.fat figure or skinny figure), based on or perception of defections as humans, we don't know if its normal to be weird or weird to be normal. Seeming how perceptions of other beings could put defections as being nice or being mean or skinny or fat.

So yea, we need defects.

There you go.

Here