You listed 3 people out of many that play feral druids. At the high level they play they can count on many things to not get trained. Better peeling from partners, for one. What are the many comps again? Two of the three you linked are playing jungle cleave. The only reason the feral may not get trained as hard is because killing the pet and sitting the hunter is the ONLY counter to hunter teams with their ludicrous, otherwise unpeelable damage.
Blizzard doesn't make balance decisions based on the minority of top x % players that play in arena. I don't think think they'll add more defense to feral any time soon, but not for any of the reasons you mention, as they're based on such a small minority.