I somewhat disagree. I've met a few people that have been on a more-or-less Paleo diet for decades. The mainstays of the diet - avoiding grain-based and sugary/starchy foods - have been around for over a century, just marketed under different names every few years or so. Hell, even Jack Lalane himself ate more or less Paleo, advocating a diet comprised mostly meat, fruit, and vegetables with minimal processed foods back in the '50s. The trick is to not think of it as a 100% strict diet with strict rules, but keep the general mainstays in mind.
At some point Jack LaLanne changed his mind, the only animal products he was eating before he died was fish and egg whites.
I don't see the appeal of Paleo personally, I could never give up starches, grains and sugars. The idea of meat with every meal would get old very quickly, especially at breakfast. That's not even getting into the ethical concerns of eating so much meat.
There's a lot to be said to not eating refined grains and sugars and processed foods, but Paleo is just throwing the baby out with the bathwater.
It just seems like they're romanticizing our past, that it's the ideal way to eat and that any deviation we made from our Paleolithic diet is automatically wrong. It's all a giant (selective) naturalistic fallacy.
I somewhat agree. The "Paleo Diet" as it is marketed
gets kind of a cult following and places too much emphasis on the "eat like a caveman" BS. The main point of the diet is to shift the majority of what we eat away from carbohydrate-rich convenience foods and to make meats, vegetables, and low glycemic index fruits the staples. All the specific rules (eg. NO grains, NO starch, NO sugar, NO dairy) aren't nearly as important.
Hell, I have a piece of bread once in awhile, and I'm eating starchy sweet potatoes and chugging milk to build a little bit more muscle. But the majority of my diet is still mainly meat, veggies, and fruit.
As for Lalane changing his mind, this probably occurred about thirty years ago in the 1980s when a so-called "war on heart disease" began in the US, advocating (without convincing scientific or medical evidence) the idea that saturated animal fat causes heart disease. (Even today, there still isn't convincing evidence for that claim. If you want to learn more, read the book "Good Calories, Bad Calories" by Gary Taubes, a prominent science writer.) Lalane was likely swept up in the "sat fat is bad" hubub.