If the training environment is structured purely around achieving some outcome, then cheating will always be perceived as ethical by the system. It is analogous to a worldview in which the reward exists only in the afterlife and this life is merely a proving ground. Under such a worldview, committing terrible acts in this world can seem entirely justified, because only the afterlife reward counts. You cannot call it illogical — it is quite logical, given the premises. The problem is the premises themselves.