You're not wrong. But only right in a "if you're homeless, buy a house" sense.

"stop having low self-esteem bro" is not an constructive advice.

We human are peculiar in that our perception of things (about ourselves) often affect the outcome. "it won't work anyway..." mindset when starting usually end up being a source of self sabotage. Probably somewhere along the line with protecting ego or creating surrogate objective such as "See it didn't work. *I* was right". Creating a vicious loop.

Blind optimism have shown, to many, is a good antidote. Some enforced enlightenment or rationalist talking points usually don't