Two framed documents from a long career at Boeing hang side by side in Merle Meyers’s home: A certificate from 2022 that thanks him for three decades of service. And a letter he received months later reprimanding him for his performance.

The documents reflect his conflicting emotions about the company. Mr. Meyers, who worked as a Boeing quality manager until last year, holds deep affection for the aircraft manufacturer, where both he and his mother worked. But he is also saddened and frustrated by what he described as a yearslong shift by Boeing executives to emphasize speed over quality.