Some people do. Also long term constant propaganda machines wear people down. It isn't hard to find people who pointed out Vietnam was bad but then supported Iraq or such. The number of people who supported the idea of setting up a universal healthcare system when voting for Obamas campaign, then also voted for Trump in 2024 is non zero.

Thankfully it isn't everyone, otherwise I think our suicide rates would grow even larger with people realizing they don't want to live in a world where they don't give a fuck about anyone but theirself.