Web Open Font Format backed by Mozilla, type foundries (ars technica)

It is not that simple to create fonts. Modern "smart" vector fonts are complex beasts, font creation is under-documented, and many minority scripts are way more complex than basic latin to support (see indic and cjk scripts). You do not have a tenth of the infrastructure or tools that exists to help someone with no formation to start churning out code. Go search the internet for relevant specs and figure out how to use fontforge yourself is not really a winning proposition.

Also, even if it was dead-easy (it is not today), people are just not aware they could do it. They know they can localize the UI because they see it localized in other languages. They'll quickly find lots of pointers to tools to help them do so. But since Mofo never made any effort to promote FLOSS fonts (and even focused on getting it out of the picture altogether with stuff like @font-face), many minority users are not even going to be aware it is possible, and assume it's some sort of black magic only Microsoft, Apple, or proprietary foundries can achieve.

Lastly, this is a chicken-and-egg problem. When you have no font for a script you have few users for this script. When you have few users you have few contributors. And if you wait till it's perfectly supported by proprietary platforms, well, few people are interested with working with you at this point. Your stuff is the uninteresting stuff which does not properly support the locale, it is very strange someone adopted it in other countries.