This assertion dismisses the ethical considerations often intertwined with legal principles. Laws (including copyright laws) are influenced by moral and ethical values, and there are often huge books on theories about the validity of certain things which serve as the starting point of collections of laws.
the immorality is how companies wield it like a cudgel to entrench their control over culture
While some companies do exploit copyright laws, not all companies use it in this way and whether it brings more harm than good is a point of discussion. But it can’t be generalized.
This completely overlooks the positive aspects of copyright as well, such as protecting the rights of individual creators and ensuring they can earn something from their own work.