...because they all suck. have a good look at the system and each description: the enneagram is entirely built on inner fears, the movement between unhealthy loops in which our behaviors make it harder to deal with our fears on one hand, cooping methods with it throughout the mid sections and various symptoms of coming to peace with them at the healthy levels. same with instinctual varients.
and if you look at the fears, they are almost entirely things which are unavoidable in life, things which a hypothetical unreasonably healthy member of society would have to learn to accept: that we make mistakes and screw up just like everyone else we judge? that our relationships are vulnerable and we are exchangable? that we aren't not as valuable to others as we'd like to think? that we aren't all beautiful snow flakes? that there's a lot we won't ever be able to know and yes some of it can bite our asses? that security is an illusion? that no matter what you'll do, pain will happen, and you won't get to experience it all? that you can't control everything in your life? that conflicts are part of it?
those are all simply facts of life that as we mature we are chellanged to accept and embrace. the enneagram tells you which part of that process you suck the most in.