Nice shitstorm, if you say anywhere that Java or any "Java" is leaching features programmers are gonna laugh at you. Java follows a simple and elegant design pattern, the developers and designers behind it want a straight-forward language with not many features/eye candies yet capable of implementing solutions for very complex problems. As I said before, features and performance may be sacrificed for the sake of the language's policy but I am pretty sure you didn't get that.
C# is very huge compared to Java, yet Java can do anything C# can, I am not gonna keep up arguing this, its gonna be like NVIDIA vs AMD conv.
About .NET CORE, I don't know what this is and I am not gonna google search this, if I want native code I will choose WIN32 C/C++ and I'm probably even gonna deliver faster than some .NET CORE wannabe. Probably .NET CORE packs a minimal and light VM into the executable or on the .NET libraries that come with windows updates and has real time hotspot. Same things exist for Java since ages and they suck, java was never meant to run on metal, the guys behind Java are C programmers.