may be tired of losing money
Aon is paid handsomely for landing the fish. Commissions generate via sales are icing on the cake. I doubt they are losing money by only selling PDP, dental or vision on a few cases but they aren't making as much as they would prefer.
I realize the agents on this forum are a small subset of the whole, but I would be surprised if agents have written enough business to make a noticeable dent in Aon's gravy train.
By choice, I only worked those who were in their initial enrollment period. I had no desire to work with GI folks. I won a few clients, lost a few. All in all I did OK but not enough to encourage me to focus on that market.