There are two meanings of ethics. On the one hand there are formal codes of ethics. Where such codes exist, there are legitimate questions about whether a particular action in a particular set of circumstances would constitute a breach of that code. These are clearly answerable by reference to the code and the facts of the individual cases. They would seem to be relevant to writing if the code was written to cover a writing activity.
The other meaning of ethics is more or less equivalent to morals. Professional ethics are rules that practitioners collectively agree to live by. Ethics are created by these agreements. But morals are things that are inherently right or wrong. They don't require an agreement to come into force. They are in force by their very nature. Of course, the problem is, not everyone agrees on what they are. Every creed, religious or secular, has its own moral code.
These moral codes are not directly related to writing, the way a journalistic code of ethics is, but they may naturally apply to writing. (Thou shalt not bear false witness. Though shalt not covet thy neighbor's goods.) The problem for a site devoted to writing is that these are actually questions about the moral interpretation of a creed more than they are about writing. These questions may be answerable, within the frame of reference of each creed, but they are not really answerable as writing questions.
Therefore I would be inclined to say that questions relating to an identified writing related code of ethics are on topic, but general ethical (moral) questions are not.