The playground needs both violence and mercy, except, for those playing right from their own homes, it's necessary sometimes, that external players get invited to help add salt and honey to the games/activities happening at the venue.
Where the players haven't been chosen or composed properly, sometimes, the games fail to produce any rewards - merely becoming distractions and hindrances to progress (sometimes even endangering health and wealth).
The question then becomes: Should each playground chose its own players? Would such a thing not render the system stale?
These and more, are the things we need to think about and address properly, to help keep this enterprise thriving.