The probabiliites being calculated aren't a priori. Amino acids exist. What are the odds of them forming a protein at random? Dembski wrote a long paper addressing your concern. You can find bits and pieces of it here
More to the point, if the idea that life is designed is a bad one, why is the alternative -- that it occurred by chance -- a good one?
No one claims they formed a protein at random.
Dembski wrote a long paper addressing your concern.
Dembski's a charlatan.
What are the odds that all the water molecules could line themselves up exactly in the right direction to form an ice crystal?
More to the point, if the idea that life is designed is a bad one, why is the alternative -- that it occurred by chance -- a good one?
No one argues life formed by chance.