That's absolutely ridiculous. Its absurd to deny reality to preserve people's feelings. One can acknowledge that mental illness is a form of weakness without treating people poorly. The problem doesn't come from the fact that people consider mental illness as a form of weakness, but from the fact that mental illness makes people less resilient to life's trials.

Pretending there's nothing wrong with being mentally ill doesn't do anyone any favors; in fact I'd argue it's worse than acknowledgement as it may discourage treatment at least as much as the current stigma.

I think the only one being a jerk here is you. Perhaps your definition of weakness needs adjustment, since you seem to conflate it with choice.