UTF-16

You're writing in a language with one of the most screwed up orthographies in existence. Convince English speakers to use a reasonable orthography, and then you can start complaining about the rest of the world.

Not only that, some of these scripts you're not supporting are wonders. Just because Arabic is always written in cursive and thus needs complex script support, doesn't mean that it's not an alphabet that's perfectly suited to its language, that is in fact easier to learn for children, then the English alphabet is for English speakers.

Supporting Chinese or Arabic is like any other feature. You can refuse to support it, but if your program is important, patches or forks are going to float around to fix. Since Debian and other distributions are committed to supporting those languages, the version of the program that will be in the distributions will be the forked version. If there is no fork, they may just not include it. That's the cost you'll have to pay for ignoring the features they want.