The only hate I remember Ingram receiving early on was due to the fact that you had better runners on the roster and Ingram was getting more carries than them. You could argue it's because he was a favorite, 1st round pick, etc.
Once those guys left and Ingram was the sole focus of the offense, we as fans had no choice but to pull for him. To his credit he ended up being a much better player later on down the line.