Missing persons

I often end up in games where one side completely dominates,

and when I look at the map, in a 30-person game I only see 7 or 8 friendly icons, making it an 8 vs. 28 battle. On the player leaderboard, I see them online, but none of them are playing. I don't understand if they're admiring the scenery or if the game isn't registering that they already left.

It's very frustrating to have to play a 3 for  1 matchup.