Bill Horne noted,
You make a good observation; at some times, society has enacted laws that may not be cheap, but which go out of their way to practice inclusion. And at other times, those laws are honored in the breach, with poor maintenance and enforcement. I'll suggest what you're seeing are varying political moods, where the group in power changes and thus practices change. The ADA and similar rules were passed at a time when there was little political opposition. Disabled veterans and other handicapped people were a politically safe constituency. So they got things passed. Then came the "tax revolt" of the landlords and the truly wealthy. They treated all public expenditure as evil, and made "personal responsibility" the mantra, as if being sick or disabled were your own fault. The ADA would not get a second reading in a House committee today. And thus there's not enough money to maintain its facilities.
The iPhone tie-in is a bit more indirect. TDDs were purpose-built to aid the deaf; until touch screens, telephones were generally friendly to the blind. Touch screen phones are actually bad for a lot of people, not just the blind! They presume a certain degree of hand-eye coordination and sharp eyesight. I wish my retinas were as good as a "retina display"! The whole Apple ecosystem is built for that world, the maybe 2/3 of the population who are most coordinated and who deal in a visually-guided tactile world. Blind people, of course, deal only in a tactile world, or an audio-guided one. And people with less hand-eye coordination put tactile ahead of visual. I am a really good touch-typist, which involves not seeing the keyboard (rule #1 of typing class is "don't look" -- typing is 99+% tactile); IOS, in contrast, is for hunt-and-peck artists whose fingers are guided by their eyes, not the ridges on the keys.
So an app that makes the iPhone usable by the blind is really clever, presumably ignoring the IOS norms and using audio and maybe vibration (I haven't seen it). And having that cell phone act as a talking GPS is also a clever concept, leveraging the phone's built-in GPS and audio capabilities along with its being able to fetch business and other site locations off of a map database.
As to having a purpose-built device instead, I suggest that for the purpose of making phone calls, a normal cell phone, the clamshell kind with raised keys, is a pretty good one. It doesn't run "apps", but at least it's a usable phone. The iPhone app makes sense, though, in that it is making use of "COTS" (commercial off the shelf) products, which are mass-produced at a lower cost than customized, low-volume devices. This is more of an issue today, when everything is on a chip, than it was 50 years ago, when circuits were wired together. It costs a bazillion renminbi to design a chip and only a few yuan to make one more. So we end up with more products that are only superficially different.
I'll also note that the clamshell form factor can support GPS apps, as it alraedy has Verizon Navigator on it. Sendero could perhaps be ported to it; the big touch screen of the iPhone seems counterproductive. But since most clamshells only use BREW, they may not be as easy to develop for, or have all of the needed functions.
-- Fred Goldstein k1io fgoldstein "at" ionary.com ionary Consulting+1 617 795 2701