If my memory serves me correctly, there was a 2k a few years ago that didn't have walking animatons a year after the previous game did. I'm not sure of the exact year but I feel like it was around 2k9 give or take a few years.
It seems to me this is somewhat a legacy issue in the sense that when certain things are tweaked it somehow affects walking animations. I'm no programmer so I'm not sure if this is actually true or not, but I certainly remember walking animations being taken out previously