Many set-top boxes cannot practically run Android since the set-top box might not have sufficient resources or contain an ARM processor. A local client application that only performs remote rendering takes limited resources and needs no long-term persistent state. This relatively simple generic rendering client can provide access to the vast array of Android apps.
In addition, set-top boxes typically don’t have complex local installations. The challenge of enabling the previously mentioned use cases is based on the premise that the Android environment can be split between a remote execution server and a local client that will provide a graphical viewer and user interaction to the server. A set-top box that has tens of apps installed by the user would create a very difficult support challenge to the network operator: running apps in the operator’s “cloud” would greatly simplify system maintenance.