The real problem with ASP.NET is that the abstraction it provides is completely divorced from the way the web actually works. It tries to provide a stateful way to program, and it is completely driven by events. Sure it exposes the response and request, but trying to use those in anything but the most trivial ways is a complete mess

It was great when I was just starting out as a web programmer and I didn't understand how the web worked. Now that I do get it, ASP.NET Webforms is a hassle at best and maddening at worst.