Many people don't get Dynamic, and what they don't get, they don't want. Some not only don't get it, they see it as a way to circumvent the type system and so hate it. As Anders says - if you don't have the types in the first place, why should you have to
have ugly syntax just because the compiler doesn't have the types.
Many others (at least used to) think that C# is just Java rehashed (I still hear this today from some people), in a way it was, but any new language is a rehash of something else. But they're not the same. They have very different generics, different ways
of dealing with primitive types vs reference types. Java generics is compiled with type-erasure. Etc., etc., etc. That these differences are constantly glazed over is just annoying.
Now, with LINQ, Lambda expressions, Dynamic, etc., we're getting much more detached. And indeed we see Java copying C# & co. Mutually recursive development, the way it should be (don't really like the word "innovation").