I dont think you can play a game like gta and expect no one to kill. GTA online is a multiplayer gta (duh) so of course people are going to attack each other. There are times I don't feel like getting into random fights and if thats the case I will go to a invite only session. Sometimes with friends, sometimes alone but point is no random chance I will get attacked for no reason. If I just HAVE to play in public but dont want to be randomly killed, I use passive mode and play smart. That means dont drive by randoms in a car, watching your radar, using your brain, stuff like that.
But honestly why play gta if you dont like chaos and epic battles. I mean its GT FRIGGIN A! The most fun I have is random fights in freemode. I don't usually look for trouble as it will usually find you before long and I kind of like it that way. Yes there is a deathmatch option but why should people be forced to a tiny map just to fight when there is a giant friggin map you load into whenever you log in.