Why ADS is stupid...do you agree?

Isn't everyone in FPSs ALREADY ADS as they walk? It looks like it. No one walks around with the gun down, they walk around with the gun up, looking through the scope. Isn't that how they do it in real life? Both eyes open, one through the scope? And when your avatar aims down the scope, is it shown in the game? Like will another player see you pick up the gun close to your face and aim? Probably not because the gun is already up and by your face and you are already aiming.

Please, correct me if I'm wrong.

Wrong. ADS isn't stupid. Supposedly "hip shot" kills are. They need to be toned down to the point of never hitting unless point black.

You are incorrect. In games that feature ADS there is a hip position and an ADS position, both for your first person view and for other's third person view of your character.

No one walks around while constantly looking down the sights of their gun (unless they are clearing a room or something similar) for several reasons: 1. It obstructs a person's view and 2. Holding something up for long periods of time is tiring on a person's arms. Eventually you're going to want to put your arms down and hold a gun from the hip, especially if there are no enemies nearby.