I had a pet betta fish with 3 chances of getting an epic 5 chances at a ultra rare 1 chance at a rare and only 1 chance at a common. Well I finally got my pet to adult and after that long and boring training session my pet gets the only common in its possible talents that is the most annoying part of training you train for a good 30 minutes and get the worst talent your pet can get. making you feel like never training again and that it was a waste of time. Which led me to think "what if you could reset you pet" then if you got your pet to mega and only got the lame talents or the ones you did not want. you could reset your pet for a certain amount of gold or crowns depending on your pets level that way you could retrain it and get another chance for good talents.
30 minutes really isn't that bad, but I'll also guess to do that you either used mega snacks or something up there. Getting common talents is just part of the game. When I train a pet, the first thing I do is check it's talents. If there's any common talents, I train and hatch (verrry long process, but well worth it) until they're weeded out.
Sometimes, though, common talents aren't the worst thing in the world. Let's use this scenario. Your x pet learned x selfish talent at teen which is set to raise max. agility. At adult, though, your pet learns critical striker. Your x pets former agility was:150. Now its: 175. Which is great for you, since agility affects the boost for your critical rating.
Resetting your pet quite frankly wouldn't be worth it, since you could just hatch again with a better pet, weed out the bad talents, so there's no chance of getting them, and train that one. If resetting were enabled at some point, it would probably be in crowns, too. (If it were in gold, it would be more expensive than hatching, since you already have the existing knowledge of 5 of your pets talents.)