Maybe the thing to strive for here is to politely challenge trite and cliché sayings, and state plainly what is minimized with euphemism.
Example: "I agree that you can't change the past, but you seem to be using that as a way of excusing wrong doing. Do you mean to do that?"
I will try to experiment with this more on my own family and see how it goes. Don't worry, I'll report back!