I understood the both have two different purposes and usage but I want to know bit more on some technical side.

What if we go with technical models where we can see Odoo managing the two different models for the Product Categories.

e-commerce categories --> product.public.category model
Internal product categories --> product.category model

Why we can not follow the single category and managing everything with boolean flag/other relation fields over the one common model.
Here why we are managing two separate models for the same.
Do we have any technical challenges with single model ? 

I am following the post  ​Odoo forum post : E-commerce-and-product-categories-separate