Someone explain the point of the revenge system to me.

Can't attack! Village owner is online!

Can't attack! Village owner is online!

Can't attack! Village has active shield!

Can't attack! Village has active shield!

Can't attack! Village has active shield!

Can't attack! Village has active shield!

Can't attack! Village has active shield!

Can't attack! Village owner is online!

Can't attack! Village owner is online!

Can't attack! Village has active shield!