but that costs a lot of money and the ones that will really fix things tend to be rejected anyway.
Yeah things which will cause massive worldwide breakage are not going to get fixed. And if it's expensive to put a new language in, well someone has to pay. Complaining it's too expensive is essentially putting the burden on someone else to pay.
It is a serious problem that some people can't write their names in Unicode,
Yeah, sure, but given that two native speakers of the same language couldn't agree, it's a bit silly to lay the blame with unicode. The thing is they're damned if they do and damned if they don't. If they try to do something without enough consultation, you wind up with Han unificaton---though I'd note that east asian representation was notably NOT absent from that whole progess. And if they don't do anything, peope whine all over the internet that they haven't.
Basically this stuff is really, really difficult and if a native speaker of the language doesn't step up to the plate to get things fixed, then it isn't going to happen.
Passport issuing services avoid Unicode because they can't enter people's names. Airlines avoid it for the same reason.
That's disengenuous, on both counts. There is no single system out there that allows everyone to enter their names. And machine readable passports are limited to capital ASCII characters, which is hardly an improvement. In both cases, the systems are vastly more limited than unicode. Snarkily, I wouldn't be surprised if the airline systems were running on EBCDIC not ASCII.