Regarding Blizzard's decisions: I really don't think that they want to force us, the few hardcore-pet-collectors, to play a DK or a Monk. I guess they rather want to give the many, many DKs and monks out there something nice for something they achieved, or some goals to reach out for. So I try to take this not too personally
Additionally, why all this "have to get all as soon as possible"? Relax. I don't really like PvP, but I do those little Tower-Worldquests (they're barely even PvP, to be honest), and step by step, I gain Prestige Ranks. I don't have a monk yet, but maybe I will level one some time - and if I don't, I will miss one pet. A beautiful one, to be honest. But with a collection of >830 pets, I don't know how much I will miss it. If the effort needed isn't worth it (subjective, just for me...), I will not collect it, and that's OK for me - a Blizzcon Pet from 2005 or so would cost a nice amount of real-world-money, so I'm pretty sure I won't get that one either. My collection is never complete. So I simply put those pets on a "not going to get that soon"-list, and I'm fine with that.
And if I ever decide to do something "exhausting" in the game only to get a specific pet, I think I'd be even more proud of it.
To be honest, I'm sad by the way the game throws lots of pets at us which have only new names for old models, I'm really willing to do something special for a special pet. Maybe not today, maybe never, but at least I can do it if I finally want to.