Thoughts on screen reader detection

I really want to thank you for your comment. I've done my best to respond to all your points, but please yell at me if I miss something.

I feel there are four areas to your comment. I've broken them down in order as they appeared. My answers are separated with "Sina" heading up the block.

You Said:
First, let's agree that identifying users with disabilities, no matter how, is only acceptable for the purposes of creating better user experiences for all.

Sina:
I can maybe tentatively agree that the only acceptable use case for such identification is for facilitating better experiences, but I feel there's a lot of assumptions in your message about the ability and willingness to do good with such information. We have experienced almost three decades spanning trillions of page visits composed of billions of humans across thousands of companies, and the universal constant across these trillions of data points is that A. leaks happen (not "if", just a matter of "when" and "how", full stop), B. There are bad actors from world governments to folks like Facebook and Google and thousands of other entities that "will", (not "may"), abuse this information.

You Said:
When the new regulations for GDPR takes effect from May 25th, a website will not be allowed to share information about their users without the user's consent. Thus, if an insurance company gets hold of this information, they will be breaking the law.

Sina:
This in no way matches my understanding of GDPR. Do you have a citation to back up this claim? My understanding is far narrower RE scope. First, it must be an EU Citizen (there's a majority of the planet now excluded), and secondly, they must be in the EU at the time of data collection (there's even more of them gone as a result). Therefore, I'm strongly disagreeing with this as any measure of safety. And, not to put too fine a point on it, but can we please be pragmatic about things that are illegal VS things that happen on a daily basis? I'm hoping we can agree that given the overwhelming mountains of evidence against virtually every conceivable industry that mankind has ever created, that we don't just think companies go around following laws, but instead perform a risk analysis of the cost of compliance against the penalty of discovery.

You Said:
You shouldn't just dismiss the benefits of web analytics that easily.

Sina:
I'm taking your comments super seriously. Let's do the same with mine. I'm not easily dismissing this. I've thought about this for decades at great length. If it seems like I am dismissing it easily, then I sincerely apologize without reservation.

You Said:
Just as desktop users and mobile users are having different user experiences, the same may be said about users who actually can see the content and those who must hear it through a screen reader. Why shouldn't we know how our site works for them before we decide what to improve next?

Sina:
This is exactly my point. That's where you should start. Knowing how your site works for someone is the first 5,000 or so steps before then differentiating user paths based on specific adaptations due to modality of access. So, let's work on educating developers about screen readers, text enlargement, switch-based computing, voice input, color contrast, keyboard-only users, etc. All of that, by the way, needs to happen after we accept, and I hope we do, that developers should write compliant code (both standards compliant and guidelines compliant against WCAG 2.0, preferably level AA).

I guarantee you that not even 5% of this potential has been realized. Not to sound glib, but it's why half the people in this comments section get the salaries they do because most content is born inaccessible, is modified to be inaccessible, and then remains inaccessible except for obviously those fantastic developers and organizations that truly strive for best practices and that have been fortunate enough to learn about accessibility. I'm not trying to insult or in any way denigrate developers. I work with hundreds, if not thousands, of them on a yearly basis, and I know for a fact their average level of exposure to these principles is virtually nonexistent. It's the worst of both worlds because they are told to make things accessible, and for most, it's the first time they have so much as heard anything about it.

Every one of us in the accessibility space has a ton of stories of when developers try to do something for the best with wonderful intentions and instead destroy the user experience due to the lack of understanding I stated above. Please believe me when I say that them knowing whether I am a screen reader user or not would not have made a single one of the 100 examples that immediately come into my mind one tiniest bit better. In fact, I can't even think of a single example of the tens of thousands I've experienced in my life in which the developer knowing I was a screen reader user, or not knowing, was the cause of the problem. Instead the causes are lack of compliant code, lack of knowledge of basic HTML and JavaScript, lack of understanding of how the DOM works in relation to assistive technologies, lack of awareness around the effects of various third-party technologies (think video/audio players, image sliders, etc.), and so forth.
I hope this helps clarify my position.