I've had the opposite experience. Played randoms and raced a lot.. Motorcycles, bicycles, parachute jumps, off road and even a motocross track. Missions and last team standing, which is fun since you only have one life. The danger of random dudes ganking you is tense, but I've killed all but one that tried to off me lol. Only thing I disliked was losing my progress after hitting rank 12 because I didn't exit properly. It only saves when you exit, so I lost an entire evening of progress.
Overall, I have had an incredible time once it worked. Yes, you can set it to private, friends or crew only, invite only, or whatever. Somehow yesterday I ended up getting strafed by a guy in a fighter jet in the desert. Out of nowhere I was napalmed and cluster bombed while cruising along the highway. I LOLd at that one.. Ganking done right lol
I just kept thinking how fun it would be with people you know, but even with randoms it never felt out of control. I ran some missions with randoms, and we all piled into a couple of cars. We were supposed to hack a keypad and steal some cars from a rich guy, but the other 2 idiots were firing shots at random cars on the way, so by the time we rolled up to the mansion, they were tailed by 2 choppers, 5 or 6 cop cars, and we had a massive shootout at the front gate

Very subtle!
I was very impressed with the overall package, and really looking forward to running missions with people I know.