I agree that these devices should be supported, but the only entity that can actually support them is apple. It's not enough for sites to work, the underlying

I agree that these devices should be supported, but the only entity that can actually support them is apple. It's not enough for sites to work, the underlying software also has to be secure enough to handle the internet. That can come from Apple providing software updates to the device to keep it secure, or Apple providing a supported mechanism for someone to install Linux, or some other operating system that can be updated. Unfortunately, apple does not provide security updates or any way to actually "unlock" them, so they are unsupported. Tailoring your site to work on these insecure clients is in a sense encouraging them to venture onto the internet, encouraging them to try other sites which might have untrusted 3rd party ads that pwn them and steal their bank cookies..... In that sense, it's more responsible to make your site only work with newer secure browsers than the reverse.