Why are parents suprised when their children do not want to have anything to do with them, if they were bad parents?
Because normal parents, despite their many mistakes, have given their children far more good than bad, and far more good than anyone else in the world. The attitude of children “not wanting to have anything to do with” their parents is due to the children overlooking the positive and focusing only on the negative. Those children are taking all the good for granted, and focusing only on how “unfair” the negative parts were.
On Rosh Hashana, the most we hope for is that the scales tip towards good to be considered tzaddik. We do not dream that the bad side will be empty. Why should we analyze our relationship with other people to higher standards than Hashem uses in judgement?