We have both altered and unaltered dogs. My tiniest chihuahuas are altered at 7-8mo simply because I do not want them to reproduce. I know people who choose to breed 2-3lb chihuahuas, but I won't do it. I won't keep an unaltered male dog in the house unless I am showing him, but even then, it's rarely worth the hassle to me personally. I just prefer housedogs to be female. I have one female chihuahua that will remain intact for a few more seasons. She had one litter in 2008, and will probably have one this year and next or the year after depending on when I find an acceptable sire. Then she will be spayed. I don't like for the females to remain intact after age 7-8years because pyometras become more common at older ages even in dogs that have given birth previously. And I don't like for them to have more than 2-3 litters.
My male LGD is not neutered because he needs the drive to protect the flock.My St Bernard is not altered because I wanted a puppy from her, but I will have her spayed after a litter or two. That is just my personal preference because it is easier than dealing with puppies repeatedly. The St. B stays in the house rather than with the flocks. She prefers to be inside with us while the pyr likes to be outside laying in the field watching the animals. If I bring the pyr into the house, he paces from door to door wanting to go back outside and guard the property.
I have nothing against anyone who chooses to breed their dogs as long as they have nice temperaments and are healthy, and the owner finds them good homes. I have no problem with altering the small (5lb) dogs at 7-8mo of age. I would NEVER alter a giant breed dog at less than 18-24 months or later. That is irresponsible as it causes life long orthopedic issues and greatly increases the risks of some cancers. I have no problem with breeders who choose to produce pets as opposed to show dogs. Pets are an important part of our society and so are working LGDs. Being show 'quality' has nothing to do with being a good pet or a good working dog. Neutering has nothing to do with improving temperament. Temperament is genetic/behavioral. Spaying and neutering are usually done for the convenience of humans. And that is fine as long as they take the dog's health into consideration.
But it's wrong to knowingly reproduce health defects and even worse to breed dogs with poor temperaments. Dogs with genetic health defects should be altered, same with questionable temperaments. In fact, very poor temperaments should be humanely culled to prevent bites to humans.