From Cambridge:
Complacency
noun, UK /kəmˈpleɪ.sən.si/ US /kəmˈpleɪ.sən.si/ also complacence, disapproving
a feeling of calm satisfaction with your own abilities or situation that prevents you from trying harder
What annoys me about these girls is their complacency - they seem to have no desire to expand their horizons.
There's no room for complacency if we want to stay in this competition!
This is the usual accusation lobbed at those who prefer the imperfect status quo over the effort, pain, and risk involved in change¹.
When I was in 5th grade history class, I vividly remember a turn of phrase our teacher used to describe Socrates' attitude towards the Athens that had accused him of corrupting the youth and sentenced him to death:
Socrates was the gadfly sent to rouse Athens from its slumber of complacency
That turn of phrase has stuck with me until today.
¹ That said, I think you are misinterpreting the philosophy advocated by the aphorism "perfect is the enemy of good". That advice does agitate for change!
What it's warning against is the paralysis or torpor induced by considering what it would take to create "perfection" -- a torpor that flows against the motivation to make any change at all towards "good".
It's the attitude that makes people misuse the aphorism "perfect is the enemy of good" to justify mediocrity.
– Guy Schalnat Dec 22 '17 at 16:54