Central to the ASP.NET MVC theme is the Model class. The Model class is used to render the view with data. Since Model is specific to a View, we used to create a standard Model (similar to DB entity) and a View Model (specific to the view). With Knockout.js, there is no need to create a View Model within the ASP.NET MVC framework.
But, here is the biggest problem of Knockout.js. If a web application does not have a consistent theme of representing data, then the number of View Models created can increase dramatically.