>>Because that's the point where you take things that don't compute, and make something that computes.

Good point but I didn't get it quite right. What is your definition of "things that compute"? I am curious.

A device that can use a mathematical process to figure something out.

A single transistor definitely doesn't compute. A single gate? Eh, not really.

A design with a couple latches and an adder that can perform SUBLEQ? Yeah that computes if you attach a ram.

A non-turing-complete pipeline of math functions? Yes, that computes, though why make that when it takes more gates than a microprocessor needs.