Your opinions are valid and I agree with most of them.EGR,DPF and SCR systems are separate emission reducing system and eliminating one of them does not render the others useless.
Once someone has a $30k disfunctional diesel he is free to choose to spend a huge amount for repairs with a questionable outcome,sell it at a huge loss and buy a gas vehicle,or drive it till it dies and take even bigger loss.Or,after abandoned by manufacturers and law makers,to make the things work in the best possible way.Different people,different choices.