People who have mutts drive me crazy. If you have a dog and you have no idea what kind of dog it is (and most people don't) there is no shame is saying, "It's just a dog".
I have had pureblooded dogs. I have had mutts. They are both great. Just accept them for what they are and love them.
Breeders are getting rich breeding dogs that just a few years ago would have been referred to as "mutts". They are laughing all the way to the bank while Joe Public smiles and says, "I have a pic-a-poo or a labradoodle." These aren't breeds they are accidents that are just another good dog.