It is usable with an IDE. Also it forces OO and interfaces down your throat, which is important when picking up other languages.

The other languages you'd choose to learn in the "Java" slot are:

- C++. I like new programmers too much to suggest this. Even if they know C.

- golang - Not a bad choice, but forced OO is a good thing to learn.

- C# - I haven't done enough of it, but it felt like Java on the CLR to me. Maybe with some warts moved around.

- Common Lisp: Too obscure, too alien to read.

- rust - No... just no. Too early.

- ML, Haskell and friends - Yes, I love you all. But... Understanding a simple type systems is important before taking on Hindley-Milner type system language.

So I'm kinda stuck with Java. It sucks the least. :)