There's something about a cookie cutter that many people like. How perfect it is, how it's handy and controlling, how it's the regular norm for a normal family.
So, they believe, "maybe my kid can be the same". Maybe they can transfer their kids perfectly in life like a cookie cutter can with dough.
But in all reality, not everyone fits that cookie cutter mold. So, they are forced, being shoved into the cutter and broken in the process, leaving them perfect but bruised.
Then once that dough is baked and life is towards its end, they are thrown away as they aren't perfect like all the rest. They are cracked and crumbled. Though, mom still continues, shoving her little dough boy or girl into the cookie cutter, trying to get a new one perfect since she threw away the last... But alas..this one is different too.
In an imaginary world, the mother would have thrown away the cookie cutter and loved the dough the way he or she was.. But instead this is reality, where being cookie cutter perfect is the only option.