The Oatmeal did a comic worth reading about this: https://theoatmeal.com/comics/believe

Some people are really loathe to do any self reflection or assessment. I gather their sense of self and worth is very fragile, and looking too hard might make it collapse.

Like, some people you could say “Eating meat is bad for these reasons” and they’ll just lash out. Not enough emotional HP to tank the hit.