My 2 sense is that you don't really need to physically assert your 'dominance' over a dog, but I do believe in being a good 'pack leader' (a solid authority figure is the way I like to see it). The way to get that status though, is by mutual respect and fair/consistent leadership not by force.
Also, to be fair, I have seen Cesar Milan use some positive reinforcement methods on his show too, especially when dealing with fearful or obsessive dogs. Although he does for a majority, he doesn't seem to stick strictly to the firm discipline method for every single case. I certainly don't watch his show and practice everything he does, but he does also make some good points, such as the use of body language (posture on a walk for example) and calm energy. Not that the article was bashing everything he does or anything like that...I just thought I'd mention some of the other things he illustrates on his program that I find useful.
Plus, Dog Whisperer makes pretty good TV...but not better than K9 cops!
There's a difference between being aggressive to an aggressive dog and being a strong leader. I don't disagree with the article, in fact, I would tend to agree with them in general, but I think they leave a lot out - although they point out aggressive training can be bad, they don't get into what is good beyond a generalized sentence or two. I think that reward based training has it's place, as does correction based training, and like most things in life, that balance needs to be sought for each human and canine couple.