While on a basic level that's true, in practice the number of complications is immense. Even just going from one-to-one to one-to-many communication makes using OTP impossible; differing delivery systems for content, the existence of add-on (DLC) content, the ability to move content from system to system (and re-authorize its use for different users), the ability to interact with external network systems, the numerous physical components of a system, and the ability to upgrade the system's functioning via firmware upgrades -- every one of these things (and many other features) represents a new potential point of weakness, and so does each place where any two such features interact. In some ways, modern systems are actually less secure due to their flexibility -- in the olden days, physical modifications were necessary to run pirated copies or unsigned code, but the PSP and PS3 can now be modified without opening the case, and the Wii doesn't even require extra hardware.