Currently we have people running their participation down by afk’ing in Spawn. (Others afk there too, but this isn’t about them)
When your run in WvW is done, or you get wife/spouse/parent/kid Aggro and need to leave the game, go to Obsidian Sanctum. You get pips and you don’t take up a spot on the map, clearing room for more active players. Only drawback is you don’t see your current participation level, but if you watch the skirmish track, you will see tick prediction.
When it shows zero, you’ve gone long enough. Or you power AFK and don’t worry about it.
Everyone wins.