Who cares what the backed is, as long as you are getting data using xhr, angular js and HTML is same.
Also, another thing that bothers me about MS is that they hide so much real HTML/javascript from devs with visual basic like facade called webforms that MS devs don't get into a new platform unless they see a document like "Angular js for .net" title.
Microsoft is moving even further in that direction with Web API, which does largely transform ASP.NET into a "dumb" REST endpoint completely separate from the HTML/JS clientside.