Well, there's some differences that do make C# seem easier and less clunky. They are similar, but not identical, and their differences do matter.
Properties. Yes, Java has getters and setters, but those are methods. C# makes the distinction between a property and method. To be fair, this doesn't really come up until you deal with reflection and more advanced cases, but it is a useful distinction to make.
Generics. Java has type erasure, which has it's issues (you can't do T newThing = default(T) in Java). If look at the lambdas, there's a lot of stuff they have to do around typing to handle primitives versus objects, etc. C# just has a Func and Action types. For APIs that use higher-order functions, this makes things a bit clearer (I want a function that takes a string and returns a bool, for example). Compare this to things like mapToInt in the streams API, and C# is just more consistent and natural in this area.
LINQ. True, Java 8 streams add a lot of this, but they don't expression tree support, which makes things like LINQ to Entities and LINQ to XML, etc. possible. Granted, LINQ has it's own issues (LINQ to Entities code can fire runtime exceptions that LINQ to Objects won't), but this power is really useful. And it requires language and compiler support to transform a lambda to a expression tree versus a closure.
In practice, it can be very useful. I was working on ASP .Net MVC 4 project. I bumped it up to five and some improvements. I then just used the asynchronous APIs in MVC, etc. It was a fairly simple change, but boom, less CPU usage and more overhead for concurrent connections. A noticeable gain for little price.
Finally, the libraries do diverge beyond the core. Entity Framework and Hibernate are different. WPF couldn't be more different than Swing, etc, really. Java doesn't have a standard library like Windows Workflow Foundation. And there are Java libraries that C# doesn't really have, of course.
While I agree that Java can get too bad of a reputation, it does show it's age. Also, the JSR process has grind to almost a complete standstill. When C++ gets lambdas before Java, it shows just how slow the process has become.
I think C# embraces newer features much more readily, and that's why some really advocate for it.