My whole thing is... I don't really see a reason
not to neuter/spay.
It does depends on the situation. If the dog is simply a household pet I see no reason for it not to be fixed. If it is a working dog or a show prospect then obviously I don't have a problem with them not being fixed. I just personally think the risks to neutering are extremely minimal. You're slightly increasing the chances of a disease that's extremely rare to begin with. It's like saying that if you eat XYZ food, you increase the chances of your finger randomly falling off by .0005%. Well, your chances of your finger falling off are extremely unlikely to begin with so increasing your risk means nothing.
I don't agree with super early spay/neuter. I think you should wait until the dog fully matures and their growth plates close, etc. And I do think, in general, there's more health benefits for a girl dog to be spayed than there is for a boy dog to be neutered. However, I will never own an unaltered male unless medical reasons came up.
The fact is there is very, very little additional health risks to neutering a dog. It's the same as the very, very little health risk you get from not neutering a dog. The risk is minimal either way. The benefits of neutering being the prevention of unwanted animals is gigantic though.
We have such a pet overpopulation problem in the US. And all it takes for that ONE accident to happen and now suddenly, you've added 3-10 more puppies to this world.
An un-spayed female and her mate and all of their puppies gone un-spayed or un-neuter can really add up. With in 6 years there can be 60,000+ puppies.
1 Year: 16
2 Years: 128
3 Years: 512
4 Years: 2048
5 Years: 12,288
6 Years: 67,000