ASP.NET MVC is probably in the top 3 web frameworks created, and WebForms is not that bad either. ViewState/Page-Lifecycle - you can use this or not - it is up to you. You can always do the HTML5 stuff in ASP.NET too, and most of the code is jQuery now anyway, so why the big fuss?
And what do you mean there is no community around ASP.NET? Have you heard about StackOverflow? The majority of the devs are ASP.NET developers there, with ASP.NET and C#/Javascript being the most tagged posts - literally every single question gets answered asap.
And what's wrong with the 3rd party vendors? They exist, support and enhance the eco-system producing some great tools along the way. Like Rasharper. Like UI widgets. Like database tools. How many times have you seen an open source project with great potential just die because there was nobody to take over and maintain it? Understand - some companies have REAL business out there - not the next social this, web that average crap startups have on $0 revenue. They want REAL partners that they can rely on and WILL pay for that. Heck, you are paying $100K to your developers, why not pay $5K for a proven software and win some time/use the resources of the partner? What is the friggin' deal with that?
Grow up. Is it like mid-age crisis? You just need switching things now and then and trying to figure out the reasons? One of the top reasons I've seen companies fail is to switch technologies just for the sake of switching and "keeping it fun" - from a business point of view it is ridiculous to invest 8 years in a framework and then just switch, like that.