They don’t want people to keep writing COM/ActiveX code, and they don’t want search engines to point you to such pages, so why would a commercial entity spend money to keep those pages around?

Hosting costs may be peanuts for them, but there’s also maintenance. Even if they don’t bother updating the look of the site, there’s the fact that old sites eventually run on no longer supported technologies that may only run on unsupported OSes, both potentially riddled with security vulnerabilities.