Have you ever had wild concord grapes KD?
They're actually very easy to eat. They are a bit tougher skinned and do have larger seeds but they're still much easier to eat than many other edibles in the wild.
As a personal theory, much in the same way that one might eschew green vegetable matter/grasses in light of consuming grass and vegetation grazing animals, its possible that eating fruits in any form in the modern period make up for vitamins once obtained from neglecting the
omnivorous animals, such as swine, birds, rodents, lizards, and bugs who all consume sugar from plants in addition to their appropriate prey. Also of course if one is neglecting whole animals parts/organs etc..
It is possible that even if we 'evolved' in tropical locales, that these fruits were not 'designed' for us to eat but for other since long creatures that were our prey.
I have never had wild concord grapes, but I've had quite a few wild tropical fruits and berries, and some fairly wild oranges and bananas. Some are indeed way more delicious then their modern counterparts and others not so much. I know that even as a 100% fruit eater that wild jakfruit was extremely sweet to me like modern candy, despite its larger percentage of fat. Ive never eaten durian off a tree but suspect the same thing. Just logistically, one can see that we are not
meant to propagate these plants, but not suggesting like any fallen food is not suitable for our flexible system.
I think what Daniel is saying even as an omnivore is that these foods -even in their optimal state but when we are divorced from natural systems and requirements- should not be a substantial part of the human diet, particularly if one is going to factor in burning fats efficiently. On top of that, yeah it matters also where that fruit comes from but that doesn't trump the former.
What it comes down to tho, with the concord grapes, is that although I find them tasty in small quantities, its a challenge to either spit or chew the seeds. If we are to accept that we would regularly consume half eaten seeds and similar fibrous matter, then we are making a whole differnt set of assumptions on what the natural diet of man is and it becomes more tenuous to rule out seeded grains and grasses and similar things. Again i'm not saying its wrong, as I believe in eating a variety of foods, often times indpendent of whether they are 'meant for us'.