WebForms (with their underlying concept of abstracting away how web really works) were already in decline two years ago, replaced by MVC.
As a former C# developer, turned Android developer, of course I have to admit there is some walled garden mentality among .NET devs, but I think they get stigmatized for that way more than average. If a Rubyist never sticks nose outside their beloved technology stack, noone makes such a big deal out of it.
Also it's nothing in compare to vitriolic anti-M$ hater mentality, often directed at developers themselves.
Or bizarre anti .NET-bias, case in point: http://blog.expensify.com/2011/03/25/ceo-friday-why-we-dont-... (I'm sure Jon Skeet was devastated).
And what's changed since 2013? Quite a lot: Roslyn... open-sourcing .NET...