I think you're confusing what I'm talking about with being lenient. I'm not even talking about new users specfically. All I'm really saying is "If you can't manage to not be a dick, or come off sounding like one, stay silent. It's better for everyone."
What drives me up the wall is the implication that that 'go out of your way to be friendly' behavior is incumbent upon anybody; the only thing that ought to be incumbent upon anybody is not being a jerk. And pointing out that something is wrong without a friendly word (but also without a hostile word) is not being a jerk. NOR IS DOWNVOTING BASED ON CONTENT. EVER. POINT BLANK.
In general, I think the whole myth of "turning weaknesses into strengths" is the wrong way to look at things. A person's weaknesses will always be his weaknesses. What he has to do is try to avoid getting in situations where the weaknesses are exploited, and focus on taking advantage of his strengths.