I've seen many breeds on craigslist and even in our paper that covers several towns
i think part of the reason is people can't always get thru puppyhood stages esp the 6, 8, 10mos ones.
also training is key...........teaching the puppy basic commands, earning respect along with laughing at times when you want to scream.
Spending more time with a dog with love and training makes a big difference too.
lastly, sometimes people's life/job living situations etc change too.
Doodles are great dogs with coupled with their high intelligence and comical abilities.........they need something to do and walks, fetch, and training is great for them. keeps them happy and then everyone is happy