To me, certain dog breeds seem too extreme and rather silly, bred for traits that serve no real purpose (toy dogs especially, although I did have a Shih Tzu once, and she was a sweet dog perfect for apartment living - an average-sized mutt with average mutt energy would have been a bad choice for me at that time) But beauty, or utility is in the eye of the beholder, I suppose. There are breeds I would never own, but I'm not going to tell other people they can't have them.
But, IMO, many other breeds are magnificent, when bred by responsible breeders who love the breed and try to look at the whole picture when choosing which dogs to breed. My favorite breed is the Mastiff, which is a breed that is currently prone to various health problems. The folks who are really devoted to this breed are dedicated to reducing these problems and are active in supporting research and health testing, and informing the public what to look for when choosing a Mastiff. As a result, the incidence of these health problems is dropping as time goes by. If you're doing it correctly, you won't make gobs of money breeding Mastiffs.
However, comparing these breeders to puppy mill breeders and backyard breeders is very unfair. The puppy mill folks and BYBs just throw any two dogs together, and sell the pups for much less than any quality breeder could afford to. Here the objective is money, not love of the dogs. And dog owners support this irresponsible behavior by trying to save a few bucks when getting a new companion.
Why do I need a Mastiff, you might ask, instead of a mutt from the pound? For starters, I love the personality - get a well-bred mastiff from a top-rate breeder, and you have a very good chance of getting a mellow, loyal companion with a rock-solid temperament that is great with children and friendly to strangers (I'm training mine to be a therapy dog). With a puppy from a shelter, you really won't know what the dog's personality is like until its full grown.
And yes, I love the massiveness of the breed - I'm not one who feels that bigger is always better, and I have no wish to intimidate people - but a well-structured, solid Mastiff in motion is a joy to behold (I love to watch mine run - his muscles ripple, his wrinkles and jowls flap in the wind - it always cheers me up) Its comforting to have 200 pounds of warm, snoring dog next to me in bed when my husband is out of town.
If you want to herd sheep, you get a good-quality Border Collie. You could spend your whole life training generic mutts and never come up with a good herder. A lab/shepherd mix will never be as good at tracking as a Bloodhound. No amount of training will turn a Mastiff into a ultra-focused, lightning-fast agility dog (although it is fun to do agility with a Mastiff, and mine loves it - but we'll never be a top champion team, and that's okay)
I've had a "designer" crossbreed before - a mastiff-like dog that was supposed to be healthier yet have the same temperament as the traditional "English" Mastiff. Guess what? That dog had horrible digestive and allergy problems, and had to be euthanized because of uncontrollable aggression (we were very gentle in our training, no punishment or painful corrections - we spent three years and thousands of dollars trying to solve his problems). I thought we had just been unlucky and had gotten a dog with unusual problems - until I heard from other folks who had had similar problems with dogs from the same breeder. Turns out she had bought some poor-quality dogs at auction, and decided to recover her losses by creating a new "breed" She didn't care about creating a better dog, she wanted to make some money (and now she sells tens, if not hundreds of these dogs every year at $1500 each) These dogs keep showing up in shelters after their owners find they're too aggressive.
I have nothing against mutts themselves, but I do have issues with the people who create them. Any dog has a mix of good and bad genes, and its a fallacy to think that mutts can't have genetic problems. There are mutts with hip dysplasia, mutts with epilepsy, mutts who get cancer. And people who allow just any two dogs to mate are irresponsible, and deserve to be chewed out. The dogs who end up in shelters overwhelmingly are mutts, and dogs from puppy mills/BYBs - its actually pretty rare to find a dog from a responsible breeder in a pound.
I will probably never breed dogs, but I've begun showing my dog. I also used to think that dog show people were hoity-toity snobs, but at least in my breed, most of them are great people who are obsessively dedicated to their dogs. Yeah, there are some jerks, but there are jerks everywhere.
You really can't tell if your particular dog is a top quality dog unless you get out there and compare it to others (I do wish that breed standards put more emphasis on temperament, though). I'm having a great time with it, win or lose - I get to travel with my buddy, we have a lot of fun together, and I've met lots of great people and wonderful dogs.
Off my soapbox now...