I know that public cloud providers like Rackspace and Azure insert their own accounts and services into cloud servers and VMs mostly under the guise of being able to support said servers and monitor them and their health.
True data centers where you own the hardware shouldn't... they give you an ethernet cord and everything is on you.
Very few people go to "true data centers". Those are very expensive because you are buying power, space, cooling and cross connects. Racking machines, replacing hard drives, building a PXE-boot infrastructure, building a remote access infrastructure that bypasses the customer facing network is expensive and time consuming.
True data centers where you own the hardware shouldn't... they give you an ethernet cord and everything is on you.