That is terrible logic. Humans evolved on the savannas of africa, where there is not an abundance of fruits. There is, however, an abundance of herd animals that can be run down by humans without tools (like gazelles for example).
Besides, their is the fact that our digestive systems are similar to meat eaters more than they are to herbivores, as well as the fact that our teeth are not tough enough or large enough to withstand chewing fibrous foods without dental care. There is also the fact that vegetarians today who think that you can live easily without meat are correct in that assumption only because the get plant foods from all over the globe in all seasons. You cannot get a complete protein from foods found in nature in most places in the world. And don't tell me rice and beans and soy or whatnot, because those are all domesticated and historically isolated.
When you talked about the fruit that you ate, you mentioned bananas, mangoes, apples, all of which were historically isolated and they are now domesticated.
You gave me the example of squirrel and an apple tree, allow me to give you an example: you and your band of hunter gatherers see an apple tree, and they see a deer. They know they can run down and kill the deer in less than an hour, and it will provide food for all of them, as well as a hide, bones, sinew, antlers, and meet that can be stored. And of course the fat deposits which you can't get from apples. True, they could take the apples and be full for an hour or two, or they could kill the deer and have meat and supplies for a couple of days. Which would you do?