It’s not just a markup fail. The URL is wrong. There is no www.purism.com (server not found). It should be https://puri.sm or www.puri.sm . It’s possible, I suppose, that whatever they were using knew to mark dead URL’s with a strikethrough?
It says something if Rex Lee (whoever he is … since they don’t have a “core team” page anymore) can’t even get the URL right.