I did not mean to offend any Neanderthals...
Other groups have flourished with a low meat diet, Hindus and Orientals for example. Their culture had very late influence in our "Western Society".
The point that you are missing is that there is an efficiency factor for producing food, the cultivation of grains allows some members of the tribe to engage in mental activities. Hunters risk their lives in their pursuit of a meal and have to keep on the search, not much time for rest or contemplation. Higher primates spend an inordinate amount of time chewing tree branches and bark to extract some nutrients and they must forage for fruits when they are available.
It seems to me that an animal has to be an omnivore to develop some intelligence.