No, it’s done partly and indirectly to supply people with dogs that fit their lifestyle. Different breeds fit different people. No one breed works for everyone. I’m always telling people looking for advice on what breed to choose to never choose a dog based on looks, because that can lead to disaster. For example, say that I chose a Border Collie because I like their looks but after buying one I found that I couldn’t handle their shy high energy, exercise needs, and/or grooming needs.

I’m disagreeing with that. Why? I’m a breeder-in-training and the one and only reason I even want to breed is to keep the dog breeds (in my case, Collies and Shelties) healthy.
I have my website:
cookiemiller.tripod.com

Line-breeding, a form of inbreeding, can be very helpful, but should ONLY be done bu someone who is knowledgeable in genetics and who is experience in breeding dogs.
IMO, the way to stop this train wreck, is to discourage irresponsible breeders with all of our capacity and to encourage responsible ones who do the proper health testing, evaluating and what the dog was bred for.
Disagree with that as much as you wish, that’s my personal opinion and I’m open-minded, but slow to change my opinions.

Modern-day breeding began in the early twentieth century. Breed standards were written and studbooks were closed “for purity’s sake.” (Budiansky 220). The idea is almost to change each breed into a separate species. However, closing studbooks is much like dropping the guillotine on a group of dogs. Inbreeding has to occur if the breed is to survive to the next generation. Depending on the number of founding dogs, inbreeding may be delayed for a few years. “If I created a breed of dogs in 1900 (that is, closed the stud book) with five hundred males, [by 2000] that breed would have been inbreeding for eighty-five years.” This is a recipe for genetic diseases and general poor health (Coppinger et al. 316). Every recognized breed with a closed studbook has a list of diseases and health problems that go with it. “It is all rather like reading an account of the royal families of Europe after everyone had spent a few hundred years marrying their first cousins” (Budiansky 216). Even worse, most breeders believe that genetic testing can help cull diseased dogs from the population. “DNA tests now exist for many single-gene diseases, and the near future will see an avalanche of such tests, and perhaps some for polygenic diseases” (Coile, Ph.D. 20). Removing dogs from the gene pool only increases inbreeding (Coppinger et al. 316).

I wrote a paper about dog breeding, and here’s the paragraph about dog breeding:

I also disagree with the popular statement: “We need to support good, responsible breeders!” Breeding is not ever done for the health of the dogs; it’s done to appeal to different people’s visual tastes. Inbreeding must occur with every breeding kennel, even with the so-called ‘responsible’ breeders. When it gets right down to it, purebreeding really started in the Victorian Era as a visible indicator of social status, and that’s still what it is.

Here’s one:
http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=17966340
(…)
. Heterozygosity is an important occurrence for species’ fortitude and survival (1). The Hardy-Weinberg Principle describes how a natural balance, in most species, maintains a high degree of genotypic heterozygosity in order to preserve genetic fitness and, hence, species’ health (2,4,18,19). High rates of homozygosity can occur in nature due to “bottleneck situations,” such as a limited gene pool in island populations, but in canines, homozygosity is deliberately accomplished by people trying to achieve specific breed standards. Many desired breed traits are recessive, rather than dominant, and require that both copies of the inherited alleles be the same for the trait to be expressed phenotypically. Individuals selected for consistent expression of alleles specific to desired physical traits results in offspring that are homozygous.

Breed purity and genotypic homozygosity is harmful to canine health because it requires inbreeding and results in an abnormally high occurrence of inherited diseases. Unfortunately, when breeders selectively “double up” on desired traits for physical conformation, they also double up on genes that can result in decreased fitness and increased disease. All individuals carry deleterious genes, but they are usually inherited in a heterozygous state and, therefore, not expressed. Because these genes are ordinarily recessive, there is no detrimental impact on health (4). In effect, a heterozygous state frequently confers a selective advantage by creating a larger store of genetic variability. Deleterious alleles are still present in heterozygous populations; however, when infrequent homozygosity of these genes occurs naturally, the individuals are eliminated through natural selection, due to their inferior fitness. The existence of deleterious alleles in a population, therefore, does not affect a species’ overall fitness (3).
(….)