Your problem is that you're trying to "get" something. You're generalising individual opinions. There isn't actually anything to get. It's just different people prioritising different things at different times.There seems to be less hostility towards adding more big cat subspecies. I don't get it.
Maybe you're seeing less hostility to adding more big cat species simply because more people actually want those at the moment. The ABB might be sitting at #20 on the wishlist, but that thing is extremely outdated now anyway - if we conducted a list today, maybe the Asiatic lion would be at #5 and the ABB at #50. If we conducted it tomorrow, it might be reversed. Who knows? Who cares? There's no broad brush. You're not missing any information, you're just seeing a pattern where none actually exists.