""Moderation in all things", says Aristotle."
Quite possibly the only thing all three of us agree with.
"What's "old" and what's "new"?"
I think you missed my very first line "forbid binary thinking"
Eat old instead of new, doesn't mean I need to spend all day ranking Jack Daniels vs Macadamia nuts therefore I MUST abandon eating salads and stick exclusively to pizza, hot pockets, and bags of pork rinds. If at the grocery store I momentarily agonize over the selection of Pears or Peaches I don't agonize for long I just grab whichever sounds better ... the solution to that never turns out to be microwaving pizza rolls.
"You reject that genetic heritage because you're squeamish?"
I reject it because I find it gross (squeamish, whatever) and my 10000 item supermarket provides me with 9999 alternatives. Well, fewer that are vaguely paleo compatible. But the point stands, I'm not 5 years old with mom saying "you have to eat your X". Variety and plenty means I don't eat it unless I want to. I don't particularly care for fried eggs either, that's OK, that leaves me with a mere 1e5 other things to cook and eat.
Its a bit different than a BDSM diet like low carb in that you don't "need" to eat three pounds of meat per day. Its more a general reordering of priorities.
Your argument is repeatedly analogous to the creationist claims WRT the missing link. OK you found a fossil filling one gap now, ha ha, now you have to find fossils filling two gaps. Um no. Well, OK you've stumped me on tomatoes vs pineapples, which is microscopically better for me, but rather than being paralyzed into a default of dorito consumption, I simply don't care because either are about a factor of 1000x healthier for me than a bag of doritos at snack time. Or maybe I'll eat some carrots for a snack instead.
Also WRT evolution not being a binary process, discussions of 500 years would only be relevant if you think the earth was created in 4000 BC. Its a little too short sighted. My oldest ancestors go back a couple billion years and my digestive system as it more or less is today is much older than 500 years. On the other hand widespread HFCS use is relatively new in the last few decades, kinda like widespread obesity. Correlation isn't causation, but given reasoned belief that chugging a 2L of regular mt dew per day might kill you in the long run, but eating a carrot a day absolutely will not kill you, its kind of a pascal's wager to eat the carrot at snack time. And there's nothing wrong with a little corn syrup once in a while ... but something hugely wrong with 40 pounds per capita per year (figure from corn.org for annual HFCS consumption, probably wildly low estimate)
Finally its a macronutrient diet, more or less, in that one individual species of apple vs another matters just about as much as the hair color of the cow you eat. They're not different enough to really matter. Its an intentional obfuscation of the issue to debate the color of cow hair to carefully avoid the bigger issue of debating celery stalk vs chocolate bar.
I will say that paleo as a diet and debating paleo is utterly incompatible with binary thinking. Its just oil and water. Religion and science.
I am very unimpressed with the alcohol citation about improved poison tolerance. As a thought experiment I would imagine we have some recent intense evolutionary pressure to detoxify lead. I propose an experiment where paleo diet fanatics exclude lead from their diet and the anti-paleo diet fanatics add as much lead dust to their diet as possible. After all, I'm sure its profitable to consume lead, and if the paleo side can't provide a detailed numerical analysis of which heavy metal is more or less toxic than any other heavy metal, we have a moral imperative to consume as much heavy metals as possible, or at least to never intentionally avoid them or encourage others to avoid eating heavy metals. My opinion disagrees. A little booze isn't the end of the world, but you're better off without ethanol in your blood.
"our monkey/ape guts tell us that we did not evolve with the expectation of eating "a relatively modest hunk of meat" for most of our meals."
I agree completely. That's why on long term average my individual diet averages out to a modest chunk of meat at dinner. Sometimes more sometimes less. Fruits for breakfast, mostly, salad for lunch, mostly. Not unusual not to eat meat for dinner. But I like it, and when selected and prepared properly its more or less relatively good for me compared to numerous alternatives, so yeah a couple times per week sure. We may be arguing about the definition of "modest hunk", I'm not talking about eating an entire chicken by myself in one sitting or something. Chicken soup, yeah that's about right. Or a salad with sliced grilled chicken on it. Not a 32 oz steak.
"That's all fine as a personal or moral belief, but it doesn't make good sense as a general "mandatory" consideration."
That's very much like arguing that you cannot order a precise numerical ranking of the quality of different exercises across a world wide range of possible exercises, for example, which is the superior exercise by numerical analysis, slalom snow skiing or jumping jacks or tai chi, furthermore not everyone has identical personal preferences, therefore that lack of universal consensus of numerical rank-ability means no one should ever try to judge the relative value of any exercise under any circumstance and no one should Ever exercise on a regular basis. 100% disagree with both my analogy, your argument, how your conclusion was made, and the conclusion itself.