Why is it soo difficult to get object classification to work on Hikvision or Dahua????

I've tried multiple cameras and multiple versions of the VMS software and its near impossible to get the object classification to work. All cameras say they are supported.  Last i checked they were the top 2 manufacturers for sales. Wouldn't it make sense to make these cameras work well with the software? I can't even count the hours i've spent on trying to make this work.