Being able to reflect on what works and what doesn't is actually the ethical thing to do so that the business' decision makers don't spend time, money and human

Being able to reflect on what works and what doesn't is actually the ethical thing to do so that the business' decision makers don't spend time, money and human resources on efforts that are at best useless and at worst detrimental to the company. Employees or (worse) freelancers who deliberately retain data and keep it away from the company are utterly unethical in that they prevent the company to assess their actions and to take adequate measures based on them, including firing them if they cost but don't provide.