I've talked with members of AH and have found out that they feel being able to check your 6 will only cause grief and worry. How many times, after all, did you see someone saddled up on you and felt panic. So, to help the world be a better place and keep the customer base from getting ulcers you will only have the forward view.
Look forward to an arena with happy, smiling pilots filled with goodwill

-sudz-
PS Your ping sounds will also be disabled for much the same reasons.
PPS For the truly unenlightened the previous post was completely bogus. Trust in the HT.