Bro, Psychology is still basically a couple of peeps throwing ideas at people and hoping it helps them feel neutral. Like.... it's really really really subjective and even if you know psychology you could definitely be wrong.
We legit still use shock therapy "because". Not "because it does this to your brain ....." but because it works 75% of the time. You don't exactly want people in charge of how much anti-depressant you have to have "Free expression and creativity" you want them to know how to help you.
The person is just talking about people who pretend like they know everything (I personally have no idea other than wow this a dodgey science). Which is a fair point. ╮( ̄▽ ̄)╭
Guys, I'm tired of encountering people saying they've studied psychology in every single manga comments section, just to justify their point, it's really ridiculous.