Good points.
> Your code is probably saved in UTF-8 right now even if you don't use non-ASCII characters.
Nit: For a document that only contains ASCII characters, UTF-8 is identical to ASCII. So calling it UTF-8 is technically correct but misleading -- you could equally well say it's encoded in any of the other supersets of ASCII.
Indeed. I had that in mind when writing my comment, but it's good that you made this part explicit.
You'd better have your editor / tools set to use UTF-8 though in case some non-ascii characters end up in your file or else you might be in for some pain.
It's not about using more or less non-ASCII characters. It's about saving the source code files all in the same encoding (UTF-8) and standardizing around this encoding.
They want get rid of an encoding mess.
I don't know how we can be against this. Your code is probably saved in UTF-8 right now even if you don't use non-ASCII characters.
It's probably just that the JDK is a very old code that was written from different OSes, without much thought on the encoding. Now, they want to standardize while making sure not to break anything.
What's more, the presence of non-ASCII characters in such a huge code base is almost inevitable so yeah, it matters if you want to avoid issues.