>>1627740They have a word for good 好 the problem is that to join an adjective to a noun you need to use the joining word 很 but the problem is this joining word implied a high degree. 很好 would mean "Very good".
So if you want to say something was just "good" you can't use 好 and say 不错 "not bad". As 不 is a joining word that implies negation of the following word.