But if you say that Common Lisp is great, there are fewer people who have really used it, so fewer people who have used it and didn't like it. And since fewer people got into it unless they really wanted to, it's easier to say "You didn't really understand it, then, or you would have liked it." The number of people who can say "No, I really got it, and I still didn't like it" is relatively small.

So far, that's just demographics. But then you get into the language itself. Java isn't an exciting language. It's not fun. It's kind of corporate and bland. There aren't many people who are really enthusiastic about Java - nor does Java give them reason to be.

GraalVM is doing some amazing things with polyglot support and native compilation.

Java's project Loom is trying to bring fibers in a really nice way to the language.

It is slowly working on bringing value types and inline types as well.

And it's got a few cool GCs being experimented on, as well as a nice foreign memory API.

Java recently got really nice improvements, multi-line strings, text blocks, local type inference, a shell, running code from source scripts and switch expressions.

Moving from OCaml to C++ or Go would be a drastic and surprising change, but it's not nearly like that.