[jfnixon]

So if the A320neo isn't suitable for a large portion of the customer base, how is it a competitor to the 737MAX 8?

[msbarnett]

It was significantly more fuel efficient on the sorts of routes the non-MAX 737 dominated, to the point where airlines and airports were starting to redo their infrastructure to accommodate it because the fuel savings were cheaper in the long run.

Rushing out the MAX let them shore up their advantage in that market — get the fuel savings AND save on the upgrades you won’t need.