Well, some might actually want co-variant return types and "real" variance instead of the interface/delegate as well as non-broken array variance, real type inference, higher-kinded types (to not loose the collection type like in LINQ) and many things more. That said, yes, C# looks a bit more familiar to Java developers although it is more or less a C++ descendant.

Additionally, most Java developers want to stay on the JVM, because it guarantees high performance, stability and maturity and has a wealth of well-known third party libraries.