I have no problem if we have an option of a changer or not, but the Worg Pup is the only minipet of its model, like it or not. You don't have a choice.
Let's take a look at what most people use as their primary argument:
-It saves space for more pet types. If there were to be a separate NPC ID for every color of every companion with multiple skins, the system would overload!
Here's why I decided to make this topic: the Lizard Hatchling in Stranglethorn. I've made it my personal goal not to keep any pets I actually care to use at a quality less than Uncommon, so I spent the better part of an hour searching for not only a turquoise-colored lizard, but also a green-quality one. It was only after I summoned my brand-new buddy that I realized this creature was a color changer, and I'd passed up tons of white-colored uncommon warpstalkers in the past.
So I looked at the pet journal. Here's the whole list of creatures that I've found, that share the Lizard Hatchling model (and abilities.)
Lizard Hatchling (of course)
Ash Lizard
Horned Lizard
Spiky Lizard
Spiny Lizard
Twilight Iguana
Warpstalker Hatchling - has one unique ability and its level 4 and 20 abilities are switched.
Plains Monitor - has its level 4 and 20 abilities switched.
Horny Toad - acts like a frog in all but its looks.
Now, there are 6 different Warpstalker skins, and nine pets right there. You can have one skin for each type, and still make several colorchangers. Why not do this, instead of making half of them colorchangers that continue to change after being tamed, and half of the beautiful skins unavailable in companion form?