How do you know which is the "best" design for a given problem? If, for example, you were given the problem of generating an image search results page of 30 thumbnails, would you load images sequentially? In parallel? Would you cache? How would you decide?
If you could harness the power of the multiverse you could try every possible option in the design space and see which worked best. But that's crazy impractical, isn't it?
Another option is to consider the order of various algorithm alternatives. As a prophet for the Golden Age of Computational Thinking, Google would definitely do this, but what else might Google do?