Caffeine doesn't detect inputs from gamepads such as the Steam Controller.

[guttermonk]

System keeps suspending while gaming. Launching Steam with the command "caffeinate steam" is no longer suitable since Steam needs to run 24/7 in order to use the Steam Controller wirelessly. And using "caffeine-indicator" is not really suitable on HTPCs since Kodi and Steam are used in big picture mode.

If Caffeine detected gamepad inputs and used them to restart the system suspend count-down, this would solve all my problems.

References:
http://askubuntu.com/q/655531/171608
http://stackoverflow.com/q/31498114/1671993

[Reuben Thomas (rrt)]

This is nothing to do with Caffeine.

Caffeine does not detect any input; rather, it inhibits desktop idleness even when there is no input.