To me it depends on the purpose and intent of the dog when I purchased or adopted the dog. I have pets and I have dogs for show/sport. The pets are altered, mixes, rescues etc. The dogs for sport/show need to be intact (possibility of breeding) and need to be able to perform (able to do the "job" they were obtained for) - this is why I got them in the first place. If a sport/show dog washes out for some reason, I will have to rehome the dog to a pet family. I cannot keep every dog - simply not feasible from a space/time/money standpoint. Unfortunately if you do it right and put the dog through the ringer when doing show/sport, many dogs will wash out. Hip/elbows don't work out, allergies, temperament not right for sport, conformation ends up not working out etc. It's just how it goes many times.
These dogs DO need a good loving home and a place where they are cherished. This is NOT a negative or a heartless thing to do. *MOST* honorable breeders will do this. Those that don't work out for the breeding/show/sport program will be rehomed to families that consider them the center of their lives and treat the dog like royalty. The person doing breeding/show/sport CANNOT keep every dog and it is a DISSERVICE to keep every dog because one CANNOT support/care for each dog like it deserves when one has many dogs.
I think it is far more selfish to obsessively hoard and keep every dog because one cannot bear to part with those that don't work out. I've seen kennels with 30+ dogs with only a few actively being worked/bred and one or two people managing the work load. Dogs don't get personal attention, they are left unworked, many times in kennels or pens for the majority of their time, and have little one on one time. They don't get to go in houses, they don't get to have a family, they don't get holiday treats, and they don't get fun outings. They just sit around day in and out in kennels/pens. Yes, they are fed and watered, pens are cleaned, and they are provided adequate care, but they exist only - these dogs are not the light of anyone's life. This is NOT an optimal life. If a dog is not actively worked/showed by a competitor or breeder, it should be rehomed to where it can be loved and cherished.
Personally, I am not looking for any more pets. I have 4 "pets" at the moment and I'm at my absolute limit for pets. I'll probably be swayed into taking another sad case...but that's another story!
I am actively looking for nice dogs for sport/show/breed candidates at all times. If the dog is desexed, I stop looking because that dog doesn't suit MY purposes, but could be a great dog for someone else. This is not to say the dog has no value, but its value is NO longer as high as it possibly could have been - that's just the practical nature of it.
Don't make value judgements on others based on your own mindset - it does a disservice to all involved. We all apprach dogs in different ways. Some for pets, some for work, some for show, some for breeding. To get irate over the fact that others don't view all dogs like you do is amusing to me...we all care and love our dogs, but we have different purposes for dogs. As long as in the end, the dog is happy and in a place where it can be celebrated for its merits is the best situation we can hope for. For some dogs, their job is to be excellent family pets. For others, it is to be breed worthy candidates that can work, show, do service, produce the next generation etc. Just because each dog has a different purpose does not mean one dog is better than another - they are suited for different purposes and we must be realistic about this fact.