With my electronics hat on: Switching electronic things on and off shortens their life. The switch-off/on cycles stress the components. The fewer times this is done, the longer stuff will last. Also, most switches are mechanical in some way, so operating them more will wear them out more quickly.
Most television broadcasting equipment is left on 24/7. This is much gentler to the circuitry, and it lasts for years.
The only time I have seen RMPs turned off was during a turnaround and crew change on a very hot day in the Caribbean, when you could have fried an egg on the centre console !