The only time I agree with this is with aircraft. Aircraft are extremely vulnerable to small arms fire in real life. But for whatever reason games decide they have the same health as a tank or submarine.
I mean, Battlefield usually has aircraft survive tanking a direct hit from AA rockets, which isn't very fun to play against. It usually leads to exactly what happens when you join a BF lobby: 1 guy hogging an attack helicopter all game with a K/D of like 145/3. Even when players pick Engineer, the kits are too specialized to provide meaningful ways of dealing damage to both land and air vehicles, forcing you to generally focus on only one. Which are you going to kit for, the land battles, or that one guy that obliterates everyone when he has the heli but can't do anything against all the other vehicles in the lobby?