You rule out the transcendental argument here and assume that direct arguments are the only kind of arguments. But Strawson has worked out the basic logic of TA and there is plently of historical precedent to entertain the possibility of its objective status.
There is nothing about a TA of any kind that demands a counter-TA. Kant's justification of morality, for example, does not compel me to provide a similar one unless he can convince me that I need need one.
What is needed is a way to apply the abstract word wrong to particuler examples of human behaviour, or a theory of ethics.
Why do we need anything other than simple moral intuition?
Sure it is possible but evaulating an ethical claim involves logical analysis
Not necessarily---there's also counter-example.
I logically analyze whether or not the Kantian can give an adequite "ought" statement.
Whereas I would prefer that you analyze whether the ought statement that he gives is adequate.