For instance fast access to un-GCd off heap memory is being added at the moment via the MemoryLayout class. Once that's here apps that upgrade won't need to use Unsafe anymore. MemoryLayout gives equivalent performance but with bounds checked accesses, so you can't accidentally corrupt the heap and crash the JVM.

They've been at it for a long time now. For instance VarHandle exposes various low level tools like different kinds of memory barriers that are needed to implement low level concurrency constructs. They're working on replacements for some of the anonymous class stuff too.

I mean, there's the obvious reason that it breaks the memory safety aspect that Java in general guarantees. The whole point of the feature is to subvert the language & expectations.

I'm not saying they should remove it, but it's pretty hard to argue there's "no good reason" to kill it, either. It is, after all, taking the worst parts of C and ramming it into a language that is otherwise immune from that entire class of problems.

Project Panama is what is driving that effort.