Kicked for inactivity in bo6 zombies

Just discovered you can be kicked from a multiplayer zombies (as the host) due to a short duration of inactivity?

Was setup on round 35 and playing privately with mates when we decided to keep one alive to take a bathroom break. Upon return, was still in the game and started moving then immediately got a “survived 35 rounds” end game screen then kicked shortly to the main menu and told I was “kick for inactivity” while everyone else remained in the game?

Why is this even a feature when we’ve been able to remain inactive indefinitely for every single other CoD zombies game