In my area (LA), I've seen a few postings like that, however, they usually don't pay well and are few and far between. Most job postings I see what some sort of full-stack experience and/or knowledge of HTML/CSS.
What would you suggest I focus on? I know MEAN stack with Angular 2 and want to work in that area and definitely with Angular 2. I guess in my area it mostly is C#, .NET and js front end using Jquery. I want to know why don't any of these .NET front end developers use a framework?
You have to remember that Angular 2 is bleeding edge at the moment. Most places that use C# and Java are going to be mid-enterprise scale businesses that can't risk using anything that new. Also, in my case, the business didn't know there was anything better. I spent the last year converting our tech stack to WebApi and Angular. Sometimes you have to be the driver for change.