Healthcare IT is one of the most backwards areas of IT to work in, I think, in large part because of the legal red tape around everything clinical. So you get a lot of people that say no automatically.
Additionally, I think you get a lot of people that don't really have an "IT mindset." I don't know about where you work but in my neck of the woods we have so many people in programmer positions that can't even write a three line script. They're great at clinical stuff because they came from there (e.g. nursing) but have no technical background...
I have a different theory: For many IT applications you can tell users to conform to the system's needs or take a hike. With healthcare (and some other government type services) you don't get that option.
If I'm Amazon and you don't have a computer? Sorry, come back when you do. No e-mail address? Sorry, come back when you have one. No credit/debit card? Sorry, come back when you have one. Don't know your postal address? Sorry, come back when you know it. No phone that can get SMSes? Sorry, come back when you've got one. Don't speak any of the languages we use? Sorry, come back when you do. Unable to pass a captcha? Sorry, come back when you can. Bad at reading and can't navigate our site? Sorry, come back when you can. Blind and your screen reader doesn't work with our site? Sorry, come back when you have a different one. Child that doesn't know their own name? Sorry, come back with a grown-up. No address because you're homeless? Sorry, come back when you've got an address.
Companies that can decline service for such people can make many simplifying, cost-saving assumptions in their IT systems.
If you can't decline service (Hospital, voting etc) you need to deal with such corner cases - and combinations of several. I can understand how getting that right would raise costs substantially.
Additionally, I think you get a lot of people that don't really have an "IT mindset." I don't know about where you work but in my neck of the woods we have so many people in programmer positions that can't even write a three line script. They're great at clinical stuff because they came from there (e.g. nursing) but have no technical background...