The choice is effectively between market potential maximization and operating economics: A single-aisle jet offers lower production and operating costs but would miss much of the replacement market; a twin-aisle could stimulate new demand but would be more expensive to produce and operate.
Most countries struggle with the usual budget limitations and a broad array of fleet replacement and new aircraft needs. But in the case of Singapore, there is a very interesting capability gap that implies a significant short-term requirement.
Sluggish aircraft industry growth is threatened by several looming macroeconomic trends, and the jetliner primes’ lofty production goals appear out of line with economic reality.