I understand what you're saying, but I completely disagree with your conclusions.Ice, I get that you know what you are talking about.
However in the past my best weightloss has come when I am involving some level of cardio combined with eating correctly.
I do understand fully what you are saying however and you will regularly find me telling people that a 6-pack is made in the kitchen not the gym.
However, what I think what you need to realise is that most people don't understand what you understand and therefore telling them that no cardio is required is not the right way to go about things. I mean technically you are right BUT people are not strict enough with themselves and lack the discipline required to lose fat by diet alone.
I personally am guilty of this, I can lose weight with diet only and have proven this to myself, however I found I had better results when I bought at least some level of cardio into my regime. I also found with cardio involved for some reason I was stronger mentally and able to resist temptation when it came to eating crap.
At present I have a lower back injury which is preventing me from doing much cardio (going to try swimming this week) and the results speak for themselves, I have gained weight (and lots of strength due to excess food too)
The reason why people are hammering away at the "cardio isn't necessary" point is that it highlights the most important factor determining success here, diet.
The reason that adding cardio works well for some people is more about happening upon a deficit that is comfortable and an activity that you can overload and. However, this only works if the person can cultivate a good level of adherence and consistency. This has required little to no thought to achieve, but it just works.
A lot of other people add cardio with similar levels of thought and get it wildly wrong, either by having their calorie intake vary because of any number of reasons or simply because the way in which they do the cardio is flawed.
It's very easy (inevitable, in fact) to undo good cardio with bad diet, but it's much harder to mess up with a foundation of a good diet. Telling people to focus on their diets and educate themselves is really the most powerful fat loss tool available, because once you "get it" everything is pretty simple (I didn't say easy!).
You also need to be aware of the amount of fat loss a person wants and the other factors involved. A person with 13% body fat is going to find it much harder to lose 3% than a person with 25%. A person with a lot of lean mass is going to find it hard not to lose this lean tissue when cutting, particularly as body fat % gets towards the single digits. If a person in this situation were to try and lose weight by doing cardio without paying proper attention to their diet, they could even increase bf%.
People really need to understand that we harp on about diet being the most important factor not because it's theoretically correct and some intangible "best way", but because it's the most universally effective method. Yes, some people can throw in some cardio and see some results, but that is more a random confluence of factors than an example that should be followed.
