I don't like it at all. I understand they're trying to get people into pet battles, but come on... this is endgame stuff. We had to go through all of Azeroth to get the Panda dailies and I still feel that is a better introduction to pet battling than nerfing the hell out of endgame stuff. Your first trainer would have pets around level 2 or 3 and they'd get progressively harder. Any serious pet person is going to go to all the maps for the pets anyway (and will probably do them for the hat) so I just ... I think it's a shame.
I truly didn't find them all that hard so that's part of my dislike.
I know that sounds stupid.
Why couldn't they have just nerfed them for level 2 and kept level 3 where it was (since it's the same pets.) They'd still need the pet battles in Draenor to get a level 3 and that's introduction enough. If they've unlocked 3 then there's no need for the nerf.