Because people fail to plan and are basically uneducated about dogs. This board is proof of that. Last night someone posted a question because her two 8 month old dogs bred. her VET told her, her 8 month old male wasn't capable of getting the job done.
Preventing a litter is not hard. Is it work? Yeah sure, more so if you have intact dogs of opposite genders in the home, but its still not rocket science.
People also underestimate the lengths dogs will go to, to reproduce.
I say if you want to keep your dogs intact that's fine, but you MUST be educated and know what will happen if you drop the ball when your ***** is in season.
Because they're lazy, are terrible at prioritizing ("I don't have money to spay!"), or are just idiots, unfortunately. None of those people are the types that should be responsible for a b---- or puppies, yet the produce many of the dogs we see in shelters.
I don't have any interest in breeding dogs (snakes and rats are enough!) so I have never kept an intact dog and never intend to. I know they can be kept intact without contributing to pregnancy, but I'm not home all the time and my dog has a dog door, so it just doesn't seem responsible or practical to keep an intact dog. Plus, I don't see the reason to.
Because they're feckin stupid. I have an intact sexually mature male Lab, and have had him around three btches in heat. I have NEVER had an accidental litter, and you know what? I'm in a wheelchair and am physically weaker than the average person.
Your aunt may not have had an oops litter but you clearly state that your dog is from an oops litter from show adults.. maybe your aunts but your too biase to say...so you should know it happens... Even to the professionals...