Same logic applicable for dictatorships and chattel slavery

Also the same logic is applicable for laws and scientific research

The fact that something 'is not "inherently" bad unless it is abused' is a non-point in a discussion about the usefulness to harmfulness ratio of anything to an individual, a community and society as whole

Monopolies cause more harm than competitive markets and are far less useful than competitive markets to the vast majority of people not benefiting from the monopoly. Not to mention the risk of abusing a monopoly is infinitely increased when a monopoly exists