If people can use the entire web in their eyes without having to update their browser (which they can because they haven't had to update yet) EXCEPT for my site

If people can use the entire web in their eyes without having to update their browser (which they can because they haven't had to update yet) EXCEPT for my site, why am I so specially that they need to update specifically for me? Bad UX. Or maybe you're in an industry where it is your job to secure users computers.