This title is very misleading. You're using the word perfection as if to discuss aspects of striving for perfectionism but what you actually mean is writing music locked to sequencer grid (mechanical).
I've never met a single performer who strives for a robotic performance void of expression. There is a case for experimental/electronically enhanced genres like prog metal, but it's done for effect, intentionally, to evoke a sound. It's not the default means of expressing a performance, but a specific feeling for a specific kind of music.
I have never met a computer musician who's tried to add performance mistakes (wrong/pitchy notes, missing beats, etc.) into their humanization methods. We add velocity changes and timing offsets, but never to make the performance sound wrong, as if the person playing sucks at their instrument. If I were judging something like that, I'd scold for doing so much work to make samples sound human only to make the virtual performer sound like an amateur.
There's no contradiction here. Everyone is striving idealistically for incredibly tight and expressive performances. It's just that in computers, the tightness is done for us, so we have to add the expression. In performance, we have the expression, but we have to perform to the best of our ability to add the tightness. This extends to cover expressions in tempo; for example, the difference between an amateur pianist doing rubato (playing void of tempo masked as expression) and a professional pianist doing rubato (playing with elastic tempo changes that keep the lines and phrases in correct proportion). This is why in proper piano practice, you're supposed to play the piece as strictly in time as possible, so that your fingers understand how it's constructed vertically and horizontally, and then you move on to adding expression and dynamic.
The problem with a mechanical performance is not primarily that it sounds unrealistic. That's a nasty side effect. The real problem is that it lacks expression. If something has expression, even though it is unrealistic, that is a lot more forgivable.