The ethical dilemma I have with the meat eating thing are the environmental consequences. Raising animals takes a crap load of oil and fresh water.
One fifth of all greenhouse gases are attributed to meat production. Our most popular meat is beef, from cows, who are ruminants who burp methane (30 times more potent than CO2). Farm animals also produce heaps and heaps of manure which seeps methane and laughing gas (295 times more potent than CO2).
Also, four fifths of all farmland is used for growing animal feed. That is not just a waste of resources, it is also that most farmers use farming methods that are not ecologically sound.
A lot of land is monoculture, with the same species of crop on the land year after year and that is draining the land of nutrients which are then replaced with fertiliser. Synthetic fertiliser is made from oil, thus adding more carbon into the system. Plowing the land releases carbon in the soil into the atmosphere.
The paleo guys unfortunately don't follow their own message: for our ancestors meat was an extreme luxury or sparingly used as a condiment.
Hey, beef steaks and pork chops were luxuries even for our grandparents. People ate more of what are now considered "bad cuts", intestines and blood products, and often in sausages. Nowadays those parts go into dog food, or back into becoming fertiliser.