Because the Paleo Diet is not a one-size-fits-all type of diet. As long as you don't eat wheat/grains/sugar, vegetable oils, legumes, etc., you can alter what you choose to include in your diet as long as your body tolerates it and if you enjoy it. You don't have to eat everything that is on that list; just keep in mind that fresh whole foods that are found in the wild and/or that have no antibiotics or pesticides or hormones added are best.
That list was one of the first lists I came across when I first looked into Paleo; and I can't believe they have "diet soda" on beverages that are allowed. What about tea? And they didn't even include coconut products. And then on "foods you should avoid" they have butter, yogurt, sweet potatoes, bacon and fatty cuts of meat?! Don't think this is the end-all, be-all list. I certainly don't.

I don't see what's so radical about that list. There is likely to be some confusion as this is based on Cordain's early work when he (like pretty much everyone else) was still struggling to fit 'modern' science on fats to the theory. You'll note he doesn't mind game meats or fish in their entirety but believed (and still does to a large extent) that the fat content of farmed animals is not representative of the meat available historically and so lean cuts are to be preferred. Most paleo folk these days so no reason to be scared of saturated fat, though the main aim is still to try and get good quality fat sources - maybe rancid, artificial canola oil is better than CAFO-bred suet. Much of our challenge today is picking the lesser of many evils.

It's only one discrepancy really though - how much of our energy should come from saturated animal fats? The avoidance of dairy, legumes, starch and cereals is just basic paleo. Anyone advocating those things readily admits that it isn't strict paleo but rather simply a related diet.

A lot of people who start researching paleo/primal diets get a lot of info all at one time. It can be disheartening to see all of these different food lists on different websites. I like to keep it as simple as possible. These are my rules:

1. Never eat - grains, legumes, anything artificial, a lot of sugar.

2. Eat decent amounts of good fat. One thing you have to remember is that on a paleo diet you don't use carbs for your body's fuel you use fat. There is nothing wrong with animal fats, butter and ghee. Don't forget good oils too. Stay away from poly-saturated oils like Canola and Soybean.

3. Dairy - in small amount and in moderation. Some of the other paleo crew may not agree with me on this one. All in all dairy falls into a gray area. It has some good benefits, and can make things taste better, just don't go chugging milk everyday. The rule for dairy is it MUST be full fat and not messed around with. The reason for full fat is that the fatter the dairy the less lactose it contains, which is why people don't eat it on the diet. I use full fat cream in my cup of coffee in the morning. Other than that I use coconut milk for everything else.

4. What do I eat? The short answer is lots of plants and animals. anything in that spectrum is good. Nuts (not peanuts they're a legume) seeds, fruits (the less sugar the better) and anything that comes from animals, meaning eggs. Eat eggs, one of the more perfect foods out there, including the yolks!

That is a great question and I hope this helped. The first thing I tell someone to do so they don't feel overloaded with new information, is to cut out all grains for the first two weeks. This alone will make you feel like a million bucks. Studies have shown it takes at least two weeks to get gluten out of your system, with a full month being even better.

This is the list I generally pass around: http://bit.ly/HzFUVq

I think the very first thing on any list of what is paleo should always be:

Listen only to YOUR body and not some list made up by someone who has no idea you are even alive.

It doesn't have to be complicated- I just tell people if you can kill it or pick it from the ground or a tree & eat it, then it's probably a good bet (barring poisonous things of course; I don't know anything about foraging and I find this to be a simple rule of thumb). Some people need to really get into the nitty-gritty and do a lot of fine-tuning, but most people will probably do just fine with focusing on just eating real foods.

The word "paleo" gets bandied about as if it refers to some singular, monolithic 1-2-3 thing. Turns out it (paleo) comes with lots of footnotes. Any of the major books (Wolf, Cordain) has simple versions that work, and that do not encourage over-thinking.

it's why the paleo diet is so frustrating but also so correct, it's more of a mode of eating than a genre, it's not strict like veganism so it's technically right for everyone

The discrepancies result from the desire of the Paleo touters to make up the rules as they go along.

A "Paleo" diet means something different to everyone. You have to make it work for you, just like Vegetarians (meaning no vegetarians diet is the same). I have found through my Paleo journey of weight loss and freedom from grains that I can eat pretty much anything that falls under the Wheat free, Dairy free, Gluten free, Soy free, White Sugar free, Legume free hood. If I want to have pineapple and sugary fruits I have them and all I want, and I dont feel bad or like I am ruining my diet because ITS FRUIT, I have already walked away from so much. I am not going to put myself through that. The same goes for sweet potatoes or the occasional white potato I wont feel bad because I had a potato its not worth my obsession on if I will gain weight. My personal Paleo belief is...It took a long time for me to become an overweight, sick, unhappy with my body person. I need to let my body have the time to work it out and get healthy again, its NOT going to happen over night and I dont want it to. I want to go through this transformation and experience my body changing. BOTTOM LINE- Dont let a food list bog you down, dont get caught up in the specifics, just stop eating crap and go with what feels natural. Fruits, Veggies, and Meats. Good Luck :)

I think some of the paleo hipster cool kids are sensing that the diet has gone mainstream and are trying to distance themselves from the masses via minor dietary tweaks (or being a "rebel" and embracing what was formerly forbidden).

But for the most part, I think once people get comfortable with the basics, they learn that there is no one size fits all approach to this. I think where the flaw in thinking comes in is where someone thinks, "hm, I tolerate dairy very well, everybody on the paleo diet should really integrate dairy."

Start with the basics for a few months (Sisson, Cordain, Wolf, etc) and then start screwing around with your diet.

Because individual biochemistry, physiology and digestion vary so much.