How about a tonal language? Or a whistling language? Or a clicking language?
I don't, however, understand why you would need support for unicode chars in the source code. To support unicode identifiers? Why would we want that?
I am non-native English speaker. Almost always we work in an international setup, so I already have to reeducate graduates from university not to use localized variable names and not to put in localized comments.
English is the de facto standard in the programs and it's mostly due to technical constraints and historical leadership in programming languages (well, there was French version of Pascal for a while, don't get me started on that ;) ). I think this made us communicate across the borders better. We already have problems of properly naming things, even limited to English, so why would we want to increase the misunderstandings?
This is blatant North American and Western European bias. It makes sense as a policy in those regions, but it is desperately necessary that computing standards do not prevent the rest of the world from participating on as equal terms as possible.
I am Bulgarian, living in Bulgaria, a small country in Eastern Europe. My native language is Bulgarian. I also know English, Russian, and a little bit of French and Turkish.
I do not want to write, or read source code written in Bulgarian, or Russian or French, or Kiswahili, or Japanese etc. I want to use one single language for that. It currently happens to be English for historical reasons.
Supporting unicode in source code, will lead to language fragmentation, and will limit my ability to participate, and to understand everything already build by others.
Please consider that as a (presumably young or young-ish) European, you have access to different educational resources, and are exposed to a cultural context where English is the lingua franca. As a Bulgarian, or any other European nationality, the only foreign language you truly need to learn to get by almost anywhere on the continent is English.
There are many, many countries and places on Earth where English is a significant barrier, due to being much further away, geographically and culturally.
While English is unavoidable after a certain level (just like French is unavoidable for a chef, or Italian is for a musician), it is crucially important that the barrier to entry does not also necessarily come with huge a language barrier up front.