How is quality possible in an organization whose job is to "enhance" software ?

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If too many changes are introduced, quality will fall off.
At the curve showing the sweet spot for the optimum amount of changes, the curve will be downward-sweeping.

Profit by various individuals will be on an upward-sweeping curve.

No one wants to begrude these individuals extra profit if quality is not significantly impaired.

In practice, it often turns out that lots of changes are put in which greatly deteriorate the product, although generating extra profit for key individuals.