Netflix announces which content will be added/removed months ahead of time. The decision to remove content is driven primarily by the principal right holders - Netflix is largely just "leasing" the shows that it presents (hence the company's shift to producing its own content).

To present it as a decision solely made by Netflix grossly underestimates the contractual complexity and involved parties responsible for turning a screenplay into something you can stream in 4K, all of whom have ownership stakes to lesser or greater degrees.