To blame it all on Van Horn is extreme. Blame it on AI if anyone. He's there leader and doesn't allow anyone else to get a hot hand by him taking the majority of the shots. Just to name 2 No.2's you wouldn't take for him are Sam Bowie and Len Bias.
There are many more but I'm not gonna list them. You can check for yourself here
http://nbadraft.net/history.htm