There are two issues here:
a) Designers trying to simplify everything beyond usefulness is a good instinct gone haywire. Simplification helps, but without an understanding of accidental complexity versus essential complexity, one is bound to end up painted into a corner with no flexibility left in the app. Few designers understand this, and those who do got it the long way round — by working on products that have a lot of essential complexity, like AdWords, and by repeatedly fighting those battles
b) An engineer's operating environment, OS, IDE, shell, terminal, is a reflection of the inside of his or her mind writ large. Like every Jedi has to build their own lightsaber, every engineer has to go through this pain of building out their weapon, because one's workflow is how one thinks, how you look at the problems at hand. No UI designer can help with that.
[0] (Because it's relevant to the context: ex-Google, ex-Facebook as professional experience)