I actually love pet collecting and Battling. It's daft, but adds something extra. I do though have a few issues with the current system,

Most of the Achievement reward Pets now have near identical doubles that you can just catch anywhere, which massively cheapens them as an achievement reward now surely?

A lot of the more difficult pets to get (including some of TCG ones) now have nearly identical looking pets taht you can just catch anywhere.

All of the rep pets can just be caged and sold on the AH so no need to grind any reps at all for pets anymore, just buy off someone that's already done them.

You can recage and sell them on whatever server currently seems to be making the most money from them. I guess this is good for money sellers, but completely ignores any markets on peoples current realms.

probably bugs -

None of the new "flying" pets can take off. Try it yourself with something like the Gilnean crow, it's dismissed when you take off, even though you can summon in the air.

Auto Summon when you dismount kills any other action you dismount with, which is VERY annoying when I stealth off a mount and then instantly unstealth again as my pet's summoned.

There just aren't really any really rare/hard to get pets any more that require a lot of effort to get :/ Maybe all the new dungeon/raid ones will help eliviate this, but I'd imagine that given a few months the AH will just be full of dupes of them all from people running the raids for rep and transmog items.