If I am actually bad enough at thinking and writing that I am a net loss to this community, as you seem to be implying, I do not see why this is so. If I don't know what you are requesting that I fix, how should I know when to come back?

Your repeated refusal to justify your claims strikes me as a form of logical rudeness. When I look at my total karma and the average karma of posts and comments I've made, I see that there is generally some level of appreciation for my contributions to this website. Why do you disagree with the consensus strongly enough to ask me to leave?