Thank you for your feedback.
In the older RadControls for WinForms versions RadChart was contained in two assemblies visible in the .NET tab - Telerik.Charting and RadChart. In one of our versions we decided to merge the code for RadChart in one single assembly - RadChart. You are correct that since RadChart does not start with Telerik, it is harder for you, our users, to find it. The same applies to RadControlSpy. Therefore, we will consider renaming these assemblies in one of our next versions.
Thank you for your feedback. I have updated your Telerik points for it. If you have additional questions, feel free to contact me.
the Telerik team