Did Saints Make Right Choice at Quarterback?

I am still surprised that the New Orleans Saints have decided to start the season with Spencer Rattler over Shough. 

They spent a high-end draft pick to bring in a 26-year-old rookie. If the Saints know they have little shot at being competitive, why not run the rookie out and see what you have?

I think everyone has seen Rattler's floor and ceiling at this point. 

Thoughts?