I am sorry about your experience at LAX. Since I did not witness the situation at LAX, I do not think I can comment on what happened to you. You contacted AA and received the response from AA, which looks like it is little more than a standard form letter they send out for a response. I do think it is very common that many companies will not discuss specific personnel matter with customers.
I do get the feeling that you are still upset about the incident at LAX. But could you give little more information regarding why you thought the response from AA was not appropriate and AA did not care about the incident?