My headcanon that I have created is that these Pokémon wouldn't exist if it weren't for the sake of them unintentionally being created. When they are created trainers are so astounded by their unique appearance that they adopt them and give them happy homes and treat them with care. Because of this the fossilmon's are super happy that they were created and love their trainers who take them on their adventure. I'm no artist but I tried to illustrate this idea by drawing a happy Dracovish!)

Who else is definitely having one of these four on their team? We must shower them with love and care despite their oddities!