Leadership...?

I often hear dog people talk about leadership. It is always like 'you need to let your dog know who is the boss' or 'the dog should not get it's dinner before you have had your supper - the underdog eats last' and 'you should be the first one to go out the door' and so on. There are many more statements like those I have listed. It is almost like people think that if they don't watch out the dog will take over the family today and the hole world tomorrow.
Agility people have also adopted this theory. They believe that if the dog leaves the contact to early it is because the dog do not respect you, not because it does not understand your criteria. To me it is just a way of blaming the dog for your poor dog training skills. All this leadership stuff has never made any sense to me. The subject really made me wonder and it led me to this question:

Can you practice leadership/domination on species which are not your own?

Ok facts - always a good thing. Dogs/wolfs are social animals which lives in packs. Within these packs they have hierarchy and within the hierarchy they have certain resources like food, place to sleep, right to mate and so on.

A pack is defined by a group of wolves/canines that live, feed, and travel as a family group.

The definition of dominance is the state of having high social status relative to other individuals of the pack... In animal groups, the dominant individual is the leader.

From this we can deduce that to be a pack, the pack members must be of the same species but not necessarily of the same breed.
The leader is the most dominant one. So to be able to be the leader of the pack you need to be a pack member and be the one with the highest social status relative to the other pack members. So far, so good...

How does this correlate to humans thinking they are the leader of a dog? Not very well.
It is as simple as this; since humans and dogs are not the same species they will not perceive each other as pack members -at least the dogs will not... Therefore they will not be able to establish a hierarchy/pack or display dominant behaviors to wards each other.
For those of you who still believe in leadership I have one question;
Can you practice leadership on a pig?
Pigs are intelligent, highly social animals who also lives i packs. I hope when I put it like that the answer is obvious.
Humans and dogs have lived together for thousands of years - Why? Because they benefit from each other. Humans benefit from dogs when it comes to hunting, herding and guarding. In return dogs get a lot of nice resources like food, a safe place to sleep etc.

One of the difference between us and dogs is the fact that dogs are opportunists. They are not objective like humans. If they get the chance they will lay in you bed or grab the stake of the kitchen counter. Some will probably growl at you when you 'kick' them of the bed or when you pull the half eaten stake out of their mouth. This is not a display of dominance - it is resource guarding. How would you react if you had just taken the last lollipop and some then snaps it from you and starts eating it? Wouldn't you say 'Hey! that's mine'? Does that make you the dominant one?
The conclusion of my previous question must be; No you can not as a human be the leader of a dog/dog pack. You can live a very happy life together because you benefit from each other. The main issue here is probably just peoples ignorance and their assumed authority and leadership (look in the history books - it's all over the place).
Speaking of ignorance isn't it quiet amusing that by looking up to words (dominance and pack) in a dictionary you can undermine what humans have believed in for decades?
If you still don't agree with me then you just keep on eating your dry biscuit before dishing out your dogs dinner - but it doesn't make a you 'the leader'.