Sounds really like a development environment problem, I mean if you can't handle that your language suddenly changes it's name in a not backward compatible fashion, how do you ever stand a chance to handle leap seconds correctly?

Is this sarcastic? Hard to tell.

Most code doesn't need to handle leap seconds at all.

So you think that Oracle must receive $200k, and that's the only way you can keep the legacy `.js` extension for your files.

The money isn't going to Oracle. It will be going to Deno's lawyers and, to a smaller extent, the US government.