Complex processes in design require intelligence. A house does not build itself, it is built. It is foolish to think that even the simplest design such as a shirt can be created by natural causes alone. Science says that although people see design, they have not observed all variables. A table could possibly build itself given the right environment and enough time.
While that statement is true, in a person's heart and mind they know this will never happen. Intelligence is a prerequisite for design.
Progress beginning with the industrial revolution and continued to this day has provided the world with wonders of engineering and technology. Computer technology and software engineering in the past 20 years has brought the world to a place once only read about in science fiction. Humans have intelligence in design to thank.
If the computer that was created in the minds of computer engineers is a super complicated precision-made piece of equipment, how much more so is a single strand of DNA? DNA is the blueprint of biology. DNA is a complex code of information locked within specific amino acids fused together and folded to form the perfect proteins which then must be placed in sequential order to create a single cell. DNA has an unmistakable nature that can only be explained by Intelligent design.
The primordial soup theory, the theory that life was created in a "soup" of amino acids, is deeply flawed. Before DNA is created, amino acids that create proteins must follow specific arrangement and behavior. Information and design exists in the nature of the components that form DNA. Even if the primordial soup theory is correct, people must come to the conclusion that biological information was pre-existent to the formation of DNA. Thus a "designer" is required.
Intelligent Design theory is not simply an argument from ignorance, but intelligence as an observed phenomenon in all forms of known design. The assumption that design is unobservable and therefore not science is ridiculous.