The issue I mainly had was that mental illness doesn't exist, or that it isn't a disease, disorder, or problem. And what that implies:

If it's a disorder, it can be treated. It's comparable to being sick even if there are no biological origins: you do what is necessary to recover, or to cope to be the most functional you can manage.

If it's just life problems, just feelings, that changes it entirely. If you can't handle it yourself, you're weak, stupid, morally bankrupt, undisciplined, a bad and pathetic person who can't handle life. It's all your fault so maybe you deserve to suffer, it's not like it's serious anyway.

That's the difference I'm worried about.