“Yet you say, ‘The way of the Lord is not equal'.”
The unusual use here of ‘the Lord' by itself (see also Ezekiel 18:29 and contrast the usual ‘Lord Yahweh') suggests that this had become a standard grievance of the people, so much so that it had taken a stereotyped form. They considered that God was not being fair to them. What they meant was that He was not fitting into the norms that they had laid down. They considered that guilt belonged to the group, and therefore to everyone in the group. And no doubt they considered that the group to which they belonged was of the better sort.
But they did not like God facing each of them up with their own sin. Of what benefit then was it that they had righteous forebears? Of what benefit that their family had a name as being ‘respectable' and ‘religious'? Of what benefit that they walked in the way of their fathers, honouring them by doing as they did? Of what benefit that they were the people of the covenant, even if they had only followed it half-heartedly? God's reply was ‘none', and they did not like it. They did not like being faced with personal responsibility, and they considered it unfair.