Holloway & @dr_mitch_kusy make this point in their book:

"Toxic people are often self-righteous. [They] cannot find fault in themselves. This is the reason that explaining their behaviors to them often doesn’t work."

https://www.amazon.com/dp/B00263ZLGW/ref=cm_sw_r_tw_dp_U_x_AIwHDb4CJFW6Q