Perfectionist ethics requires one strive for excellence or "develop [one's] nature."
However, one particular passage in the linked text seems problematic when trying to assign values (right or wrong) to actions based on perfectionist principles:
The possibility of self-regarding duties of this kind are sometimes rejected on conceptual grounds. Moral duties concern one’s treatment of others, and so a moral duty to oneself is a confused notion. But this worry should not detain us for long. The key point is that we can have categorical reasons to develop our nature or to engage in valuable, as opposed to worthless, activities. It is a secondary issue whether we should classify a self-regarding duty as a moral duty or as (merely) a categorical non-moral duty (Raz 1994, 40). But while the worry should not detain us, it does point to an attractive feature of perfectionist ethics. Much contemporary moral theory ignores duties to oneself, whether understood as moral duties or not, and focuses exclusively on our duties toward others. Perfectionist ethics is an important corrective to this tendency. By expanding the domain of ethical concern, it has the potential to enrich contemporary moral philosophy (Hurka 1993, 5).
How is an agent to regard themselves after violating self-regarding duties? Under perfectionist moral ethics, can a person who is outwardly kind, but who doesn't fulfill their self-regarding, non-moral duties call themselves "moral" or "good"? Should they call themselves immoral?
What does it mean to violate one's own self-directed, non-moral principles to strive toward excellence. Is purposely choosing mediocrity wrong under perfectionist ethics?
edit: I suppose I should clarify that I do understand that a person who advances toward excellence is moral under perfectionist ethics. However, it's not clear to me what to call someone who fails to strive toward excellence. The text never explicitly states that people who don't pursue perfection are immoral.
In particular, I wonder what perfectionist ethics has to say about individuals who lack the discipline to strive for success (due to weakness of will, or akrasia), but are nonetheless kind and altruistic. Are such people really considered immoral (a word I would usually reserve for such transgressions as lying,cheating or stealing) or, are they merely misguided? It's an important distinction, because immorality may give cause for retribution or rehabilitation; an accusation of immorality carries certain weight.