I agree with you and disagree with Stephenson. From TFA: "Sixty years and a couple of trillion dollars later, we have reached a place that is infinitesimally close to the top of that hill. Rockets are as close to perfect as they're ever going to get."

From what I understand of the rocket business, this is completely wrong.

Current rockets designed by the established players (LockMart, etc.) are optimised for performance, not overall cost. This comes from a variety of factors, starting with the basic philosophy of the designers, to the rocket fuels chosen, all the way up the design hierarchy.

I estimate that it is possible to reduce launch costs by at least 10x, and that is using 1960's rocket technology with modern computers and sensors. The key is looking at what is going to reduce overall operational cost. I don't have room to explain everything, but suffice it to say I'm a fan of big dumb boosters.

There are many, many political factors at work that have slowed down the cost reductions which we would see if this was some other industry. One of the biggest factors is that the major governments don't really want launchers to become cheaper. Again, it gets back to the space race, and the governments don't want just anyone to have ICBM capability. The big companies also don't want competition for their cash cows, so they lobby hard to make sure space access remains as expensive as possible.