It's not the fact that they are kids that bothers me, but the fact that even the grown-ups play the game in the worst kind of childish way (not I don't really expect kids to act non-childish either). When freeroaming I actively avoid any contact with other players because they try to kill you even when they have 0 reasons to do so. Hence why I also fully support the bad sportsmanship punishing system. If anything, it should punish more things than just blowing up personal cars. IMO refusing duels after you killed someone for no reason is bad sportsmanship too. Also, not a single race happens without idiots ramming each other and me (the way drafting works really doesn't help, the game would be better with 0 drafting). This is amusing considering that until now I won all my air and boat races but keep frequently losing land races because for example when I'm 4th, the 5th guy keeps thinking it is a good idea to ram me and send us both in a wall.
Another thing is that even though the missions are not easy to do alone (which is nice), it's usually because they involve the horrible concept of infinitely respawning enemies. In many missions, you must drive somewhere, kill people, retrieve something then drive somewhere else. The problem happens when after you grab whatever you need to grab, suddenly there will be two SUVs with two enemies each that will spawn nearby and follow you everywhere on the map. If you kill one, another will respawn near your current location. If you shake them, they will respawn too. This is especially dangerous on the motorways where they will spawn in front of you and on your lane. This is a completely stupid way to add difficulty because the only way to "deal" with them is to kill the guy who isn't driving and making sure you don't shake them while driving to where you need to go.