This is to avoid players from spamming bounty when ever they die.
Mostly on Teamfight... which is mostly where all fight happens...
People were abusing of KSing for hours on your spot so you take the skull and they would use /go with multiple lv 90+ to kill you to make you lose 10% and they would do that Non-stop for hours...
Until there are no other way to avoid the -10%, it shouldnt be used...
Its a PK free game, not any other MMO... Pk is the main focus of this game, take it away and 80% of players wont play to just farm for sh1t they cant use...