They're addicted to blowing people's shyt up, breh. Plain and simple.
It took me a few solid months of doing a work around to get into private lobbies before they gave you the option to select it on purpose, but the chaos of fukking people over for no reason, cheating and going godmode while making vids on, believe it or not, is a very lucrative thing online, hence why it's still getting spin to this day.
I earned about 300 million grinding the Motorcycle club businesses (Weed/Meth/Coke/Cash) to the point I've every major purchase, from Submarines, to COD AC130's I can have 4-6 men (pause) up in raining hell down on people, to that Hammer of Dawn satellite canon that can blow anyone anywhere up on the map and I log in with friends and we fight fools who look to pick on smaller/lesser players (Smurfing) just for our own shyts and giggles.
It's all about griefing, breh. The creativity in businesses, missions ran out years ago so now everyone in there is on some Carcer city, psychopath shyt that you got to be rich or a sweat to hang with.