what r u talking about, archer, xbow, throwing, lance,hidden pike can all kill HA.
now perhaps...anyways, the HA was not imbalanced in my POV, just the problem is, once the people saw someone on horse with bow performing well, they want to try it too, its good, better than foot archer as you dont have to walk around slow, and as the guys were getting better and better and more importantly: more coordinated, the HA became pain in the ass....when u tried to get to some town to get a cover just to be raped few second and meters before by 5-6 HAs circling you, that was not fun...
In the huge battles on some maps, one or two good HA can make a difference. Iirc chadz said that EU were flooded by HA, so there was needed to make something to prevent it from spreading even more. I believe good players will get used to this again, so maybe the numbers of HA will decrease over time.