Dislike Boeing's decision to follow Airbus and reengine its single-aisle product? You are not alone. Many analysts and commentators have expressed disappointment.

“The decision has been in favor of a quick fix, not the bold stride aviation needs,” according to Aviation Week & Space Technology's Aug. 1 editorial (p. 54). The Airline Monitor's Ed Greenslet said it was evidence of a “risk averse” culture that chose to “modify old products rather than launch new ones.” Just before the Boeing announcement, Morgan Stanley said a new airplane was most likely, adding, “We have not encountered much support, publicly or privately, for a reengined solution.”

Yet market reaction tells a different story. Before Boeing came in with its last-minute reengine bid, most reports indicated a clean sweep for Airbus at American Airlines. Clearly, the new Boeing product saved the company from losing a key customer. Gary Kelly, CEO of Southwest Airlines, one of the world's biggest single-aisle operators and launch customer for both the 737 Classic and NG, told Bloomberg on Aug. 4 that the carrier wasn't in discussions with—either Airbus or Bombardier. Kelly added, “I've said consistently we are working with Boeing.” There don't appear to be any obstacles to Boeing maintaining its customary half of the single-aisle market.

This divergence between expert reaction and market reaction to the reengined 737 has its origins in our industry's demographics. Aviation is divided into two not-always-exclusive camps. One group—call them Technologists—thinks of aviation as a technology-driven business, with new equipment stimulating demand and therefore creating its own market. At the extreme end of the Technologist camp, you get people who lament Concorde's demise.

The other group—call them Economists—primarily views technology as a means to an end: profit. Most airlines and aircraft companies are run by Economists.

For the Economists, AW&ST's call for bold strides raises three questions: What are these single-aisle strides? What do they cost? Do those strides give manufacturers the added pricing power to pay that cost?

Beyond 2020, there is a broad array of new airframe shapes and materials and subsystems coming, but Airbus's A320NEO (new engine option) shock-and-awe sales campaign means that Boeing needs a competitive response by 2018, at the latest. For a new aircraft entering service before the end of the decade, there is a limited menu of new technologies. New engines represent the only major new technology that will pay for itself. The others are either modestly incremental or simply not worth it.

As an interesting object lesson, consider Bombardier's CSeries. It offers the latest and best new technology for a single aisle. It's the only one on the market with composite primary structures, as well as a very high ratio of advanced materials. After three years, market reaction has been underwhelming, to put it charitably, with just 133 firm orders. The biggest single order for the CSeries comes from Republic Airways Holdings, with 40 CS300s. At June's Paris air show, Republic also ordered Airbus's A319NEO, a direct competitor, putting a question mark over its commitment to Bombardier. The CSeries may prove that new technology garners no rewards in the single-aisle market.

Consider the choice from Boeing's perspective. For about $2 billion in nonrecurring costs, they get a reengined 737 that apparently meets the needs of key customers. For about $8 billion, they could get an all-new single-aisle with one big enabler: the very same new engines found on a reengined jet and on competing jets. They also could get a variety of nice-to-have enhancements, such as a slightly wider cabin (which would increase weight), more composites (which may not matter on a single-aisle) and fly-by-wire controls.

If Boeing were to go with an all-new jet, it would need to find a way to amortize that $6 billion premium over a reengined product. Good luck with that. Single-aisle jets cater to an airline market with razor-thin margins. They are commodity products for a commodity service. Consider too that this decision to launch a new product would divert Boeing's resources from new higher-profit twin-aisle jets.

In short, Boeing made the right move with its 737NE. Saving $6 billion, even in aviation, is a lot of money. The next time you hear someone arguing for a new Boeing single-aisle, keep that number in mind, and ask how it would be repaid. As Oprah Winfrey would say, this is a teachable moment. Technology fans must recognize that new equipment needs to earn its keep.