Category.ByName is for when you simply type in the Category. So instead of feeding in the ‘dropdown’ menu, you would have to type in the ‘Under the hood’ name. Most of these start with OST_ which refers to Object Style.
Walls for example are ‘OST_Walls’.
So for your example, you’re feeding in simply ‘Generic Model’ instead of ‘OST_GenericModel’ (I’m not entirely sure that’s the OST name but it probably is).