Honestly I think cross-site requests were a mistake. Tracking cookies, hacks, XSS attacks, etc.
My relationship is with your site. If you want to outsource that to some other domain, do that on your servers, not in my browser.
My relationship is with your site. If you want to outsource that to some other domain, do that on your servers, not in my browser.
But then we would have had to educate users, and ad peddlers would have lost revenue.
Of course it was only later that cookies and scripting and low-trust networks were introduced.
The WWW was conceived as more of a "desktop publishing" metaphor, where pages could be formatted and multimedia presentations could be made and served to the public. It was later that the browser was harnessed as a cross-platform application delivery front-end.
Also, many sites do carefully try to guard against "linking out" or letting the user escape their walled gardens without a warning or disclaimer. As much as they may rely on third-party analytics and ad servers, most web masters want the users to remain on their site, interacting with the same site, without following an external link that would end their engagement or web session.