I respect the author's (No Springs') important message, and especially the two points of advice given, which are well-stated. I'd like to offer some of my own perspective as a bipolar individual.

How can I really condemn a person for acting in a way that is very much a part of her nature, a part of her illness?

I'm not sure about this wording. I think it is worth pointing out that, at least in the case of mood disorders such as bipolar, it is valuable to consider someone's illness as quite separate from their nature, at odds with it even.

... [D]espite best intentions, we are who we are, and some mentally ill individuals (even when medicated) simply lack the capacity to see their own actions with any type of perspective or introspection. ... [T]hat's the nature of the disease.

I would not wish someone to infer that the effects of a mood disorder on such capacities are fundamental and not treatable with medication. Such effects are a dramatic result of an imbalance in brain chemicals that can often be treated. For example, when I have been manic, my thinking has been irrational, inappropriate, irresponsible -- but this is not part of my "nature" at all. Medication these days is very good, and I would like to believe that any bipolar person can be helped and lead a normal life as I do, free from such unnatural tendencies.