Udyr stuns Alistar during headbutt, but Alistar can't auto attack afterwords anymore

I don't know if this is intended, but I don't see how it is fair that Udyr can hit Alistar during headbutt and Alistar no longer can. If they removed Alistars ability to auto attack immediately after hitting someone with headbutt, it only seems fair that they do the same for people trying to hit him after headbutt. Udyr's bear stance renders headbutt worthless against him because he just stuns Alistar and catches right back up to where they were in the first place. I think they should either add back in the headbutt + auto attack combo or remove other people's ability to hit him after it to make things even.