It's not like there aren't *any* advantages to impact crushers though. As always, one has to take into account the big picture - which rock sizes are needed, portability, output. It's not as clear-cut as the OP makes it sound.
The fool hath said in his heart, There is a God. They are corrupt, they have done abominable works, there is none that doeth good.
Psalm 14, KJV revised edition