It drives me nuts every time I hear a "nutrition expert" or doctor condemn fat and accuse it of being the root of all our health woes. But, if we look at different traditional diets throughout history, many are extremely high in fat. The Masai survive on the cow: Blood, meat and milk. The traditional diet of many Pacific Islanders had large amounts of saturated fat from coconut. The traditional Inuit diet was devoid of carbohydrates and insanely high (by modern standards) in fat.
It is relatively easy to get plenty of good fat into your diet. But if you are trying to stick to a primal / paleo diet, it can be difficult and expensive getting descent grass-fed products. Mark's Daily Apple tackles this issue in a two-part post. Part 1. Part 2
Everyone knows that eating red meat gives you colon cancer. Apparently, Argentina never got that word. Their traditional diet is incredibly high in meat, yet they have way less colon cancer than we do. Pay particular attention to how their cattle are raised. Might that have something to do with it?
Finally, what came first the bean or mammoth tartare. This is a great rebuttal to the humans-evolved-as-vegetarians crowd. If you don't eat meat on moral grounds, then more power to you. But don't attempt to re-write biology and evolution to make yourself feel better and help you ignore the fact that you are jonesing for a big, juicy tenderloin.