[crescentfresh]

Kendo is indeed a "fork" of many things. Knockout, Backbone, underscore templates with different delimiters, bootstrap, many existing ui widgets (chosen comes to mind). About the only thing they didn't fork was jQuery itself. But at least you get all of the above in a single product. I guess that's a bonus?

I have personally fought to work around their widgets more times than I've worked with them. And have dropped integrating their widgets into new projects, to avoid the bloat/overhead.

[junto]

We are still using the original ASP.NET MVC extensions that they released as open source before they went on to develop Kendo.

I've used a fair few .NET controls from various vendors and they all are challenging in different ways. The common problem is that they force you to do things in a particular way.

If I was to rebuild our product it would not be using any of this heavy backend style server controls.

It is history as far as I can see. JavaScript front-end frameworks and REST services even with .NET is where Microsoft seem to be headed as well.