Yes, exactly! It frustrates me that my winterspring frostsaber is only green, when it's been one of my top performers all along, and deserves to be higher quality.
It's also nice to be able to upgrade green pets you might have dedicated yourself to leveling in lieu of trying to find a blue. I have a few white or grey pets that I'd love to upgrade since trying to farm for better quality is just impractical. Like, for instance, my wanderer's festival hatchling. The place was crawling with collectors and I was lucky to even get one shot at a pet there. Or trying to find a decent stowaway rat in Deepholm.
I'd rather hunt wild blues, but it's nice that we have a chance to upgrade select pets.