This is balanced because you still cause staggers (most of the time). This allows the real heroes of the battlefield to win. Didn't anyone tell you? Archers are support characters. They're more like cheerleaders, while the melee classes are the real athletes. What, you actually want to do damage? You're using the wrong weapon then.
Damage to horses will probably be reverted at least. Cavalry are supposed to be support too, so it's OK to hurt them.
I think you are exaggerating here.
In my opinion archers really shouldn't do too much damage, simply because you don't need to make a mistake to be shot by an archer, unlike melee where you can block and even fight back.
I agree that you do too little damage atm, but this is about to be tweaked a bit, so you should do fine as soon as the next patch comes out.
I retired some time ago, and from ATH 8 I am now on ATH 5 (approaching my build's maximum of 7), and I find it particularly difficult to dodge arrows. It was much easier for me some time ago, but now mtemko can shoot my from horseback over 50 meter (and over the heads of 10 other players) twice in a row, killing me, while I am running around and dodging like mad. (I knew he was shooting me).