I don't really like hare meat for that reason. They are much too lean to make it worthwhile. I much prefer bird meat or some other type of fatty meat, birds seem to have more fat content every time, If I have to eat lean meat I prefer pigeon or dove over hares when I have a choice. All the hares I have eaten have been extremely lean and it seems like I expended more calories in the hunting/setting up snares than I obtained in eating their fat-less meat.
I have read those stories by Calvin Rutstrum and others about the old-time trappers living off lard/butter and lean hare meat when they couldn't obtain any fat meat but I wouldn't eat that as a staple unless I had to.