In my case:
Orc: Much as I liked the piggie, it wasn't my favourite skin, so I sort of "recreated" him by running to Mulgore and getting myself a brown armoured one. And not on fire either. It was cute using the boar, with it's adorable animations, and I definitely bonded with this one more than some other starter pets.
Human: I got mine to 11, and during that time the wolf did nothing for me. I was planning to rid myself of it as soon as possible.
Dwarf: On Ethel, Malt became one of her main men. I love that brown bear and it's "intelligent eyes", as someone here on petopia has named them. Still, I deleted her, and recreated the Dwarf for nostalgia reasons to look like my old Warrior, and for her I intend to get the black bear instead.
Tauren: I really like that tallstrider model, but it just wasn't working for me. They're so ridiculously small next to Taurens. It was yet another nail in the coffin for this tallstrider skin.
Night Elf: Anemone and I bonded to some extent, I have to admit. But like Sam, I consider it "cheating" to have this rare skin as a starter pet, and since I had several more tiger mount skins planned for Lomelinda, I let her go. Will tame the skin on someone else later.
Draenei: The moth just wasn't working for me at all. I think that moth may have been the biggest reason I deleted the hunter.
Goblin: I really dislike the old world crab model, and both times I've leveled a Goblin Hunter, the animal has gone bye-bye the second I can tame something better.
Worgen: The dog and I weren't clicking, though I love mastiffs in real life. I did feel a small wrench in my heart when I let him go, since story-wise we'd been through so much together. Still, can't say I've looked back.
I'm very grateful to Blizzard for letting us have a starter pet in the first place, since I remember all too vividly the days of eternal kiting to level 10, but I'm a huge fan of customisation, so if that was actually available for starter pets, I'd probably have to go make a hunter or two more.
