so why to stick with ascii

Because it works everywhere, unlike any of the various other character sets. Using non-ASCII characters in your code is stupid because it restricts *you* to only using certain machines (you won't be able to just borrow a terminal from someone and fix a bug); and it means that a *huge* number of your users won't be able to contribute patches. Using ASCII is lazy, in a good way.

You might at this point start to rail against "neanderthals" who don't use your chosen flavour of character encoding. People say that to me a lot. It's funny though, they all blame my "obsolete" software. They are all Dead Wrong, as my oldest machine was set up just three years ago, which is well after the invention of all the various incompatible encodings that everyone seems to think I should use (although they all have different opinions about which one it should be).

And of course, your chosen flavour of encoding is precisely that - your chosen flavour. Other people with whom I deal have settled on other encodings.