For good or for bad, the only way I have seen the pet in cabin fee waived is if the owner claims the animal is a "service animal" and provides "emotional support" to the owner during flight. I was wondering why the pet was not in the carrier in the gate area of my small airport, then saw the anaimal again taken out and cuddled by the passenger in-flight.
The agent told me that they see more and more "service animals" in this regard and basically can do nothing about it. I wonder why there were not as many such service animals when there was no pet-in-cabin fee or when the fee was lower??
They are afraid of discrimination lawsuits. For years Disneyland offered a line pass to anyone with a doctor's note saying they had ADD. You walked up the exit line and got onto the next car available to ride. So many people learned about it that they changed the policy and now offer "reservations" so you don't have to stand in line and suffer from your ADD or inflict cruelty on all the non-ADD people in line....
I always wondered, though, about people who have allergies. Why do they allow pets on at all? Even service pets are seemingly unnecessary given the number of wheelchairs I see in use these days (I saw nearly a dozen on a recent flight). I would love to travel with my two Labradors but that seems like a burden on everyone else on board. How about if I buy them their own row? Can I just put up a gate and keep them in their "seats"? (just kidding of course).