That's just when it got to an unbearable point. It has always been an issue. The third person we have now was changed for a reason. It isn't needed to play the game, just an addition for those to look at their player model for issues and such with their player model.
The current map's skybox is so low to the ground, it is almost impossible for staff to fly high above action to spectate it, so adding helicopters and planes would not work at all on this map. As well as it would cause more lag on the server. It is an interesting idea, but those were the main reasons I remember it being removed back in the day, and those reasons haven't changed I don't think.