I've talked to a lot of trainers on approaches to training and the ways dogs live now.
Training techniques -- uses of chokes chains and basing approaches to training on notions that dogs are trying to prove their 'dominance' -- only go back to around post WWII. Dogs were not trained like this before then (but back to that in a moment). Dogs also didn't get or perhaps need a lot of formal training because they had regular, often constant, human companionship during the day. One adult was generally home all day, and kids didn't sit inside watching a box, be it a PC or a computer. They went outside -- with the dog. Most family vacations, the dog went with people, because people didn't flyaway and spend two weeks abroad -- the dog went along.
A dog's life now tends to consist of spending many hours alone -- often most of its life is spent asleep at night then home alone all day, and home alone again when people head off to do things on the weekend. Kids might play briefly or sit with the dog inside, but kids are not outside for several hours every afternoon and evening, with the dog,as would have been the case even when I was a child. Kids don't even walk dogs anymore because parents are paranoid about having the kids go anywhere alone. When I was younger it was mostly the kids who walked family dogs, or the dog was walked as a family. We kids took the dog to the local parks too. Now, again, the dog mostly sits inside.
Bascially our lives have changed significantly and don't suit dog ownership. That doesn;t mean you shouldn't have a dog, but it DOES mean people need to make the commitment to this living animal which *isn't* just a decoration for the house. We all need to set aside the time to give the dog the life it needs to remain mentally stimulated and fit. Whether that means hiring someone else to walk the dog or for people to reshape their day and evenings and weekends is up to the owner, but doggie daycare while good for keeping the dog in company is not a form of exercise either.
On this point I totally agree with Cesar Millan -- people get dogs then do not give them the physical or mental challenges they need to stay fit and mentally healthy. A lot of us give the dog a life that is the equivalent of plopping a child in front of the TV all day long because it is easier for us. They need an hour of activity. They need interaction that is more than popping treats in their mouths.
The fact that they don't get that level of active interaction with us on a daily basis, and have lots of pent up energy and are understimulated, leads directly to training and behaviour problems. A bored, underexercised, understimulated dog is a dog that barks, digs, chews, whines, fights, roams, has housetraining problems, gets too fat, picks up quirks we don't like, etc etc.
On training methods and going back to what has happened post WWII: I think there's a reason certain breeds of dogs are now becoming more problematical (and I DO believe there are breed-related issues, I am not one of those who thinks it is 'only' the dog and not the breed -- I know from experience how hard it is to NOT have a cavalier that is generally friendly and sweet tempered and a velcro dog. Many of us know collies that nip heels and try to herd despite never having been trained to do do, and terriers that are good ratters by instinct. If the dog instead has 500 years of fighting breeding in it, then it is hard to breed out dog aggression...BUT -- and this is a BIG but -- well socialised former fighting breeds don't have the tendency to fight.).
The thing is, many of the breeds we now read about in the news all the time were always popular pet dogs in previous decades. Then we started to get these breeds and not give them mu ch time nor get them out and socialised with dogs and people as would once have been the norm. AND: the dominance/man-handling began -- training methods which the above articles would indicate work dangerously to provoke the dog and humiliate the dog in such a way that it obeys through fear... but may then lash out at others. So many trainers I know have to deal with dogs that are now fear aggressive due to people having trained using dominance (Millan style) methods.
Pit bulls and other bull breeds for example were one of the number one family dogs in the late 19h and first half of the 20th century, because they were gentle and affectionate with children. You see them in pictures all the time -- a pit bull is the dog in Little Rascals too. If the breed had had bad associations it would not have held this strong position as a family dog. German shepherds were another extremely popular family dog.
Now we seem to have some strange need to bully the dog rather than reward as a training method, using these TV methods. If you've ever been bullied you know the frustration and anxiety builds and builds. You see the same in dogs. Maybe trying to boss and bully the dog and exert physical control over an animal suits a Me Generation mindset that wants immediate gratification ('I have a right to own a dog') and fast results ('I don't want to put any time into training based on a close bond and motivated response, when jerking a dog on a choke chain works faster').
So: people get dogs for the wrong reasons and keep them in inappropriate, unstimulating environments. This creates a dog with behaviour problems which training methods based on fear and punishment can quickly suppress at least in response to the trainer. But to me, that's not training, and isn't any real life for a dog. I am old enough to have watched dogs trained decades back with these old methods, and with positive methods now -- and there's a world of difference. It depresses me to see TV trainers once again bring credibility to a rather sad way of training that does damage a lot of dogs and definitely incites higher levels of aggression in some.