This is a "...and don't call me Shirley" level of logical interpretation of what they're saying. They are pointing out that "just try harder" is NOT going to work.
This resonated with me as I spent my whole life telling myself some version of OP's "stop making stupid mistakes" daily, and then castigating myself when I continued to make those mistakes.
Then I got a great therapist who helped me realize that I need to work with what I got and I'm SO much more productive and comfortable with myself now. That doesn't mean never getting better, and like smugglerFlynn I had a strong reaction to OP. He reminds me of myself, and I see him heading down a path that caused me a lot of pain.