In the early days of the internet that was actually the correct way to do things. Websites were supposed to be hosted at the www subdomain, while other content was supposed to go to places like ftp.whatever.com. Technically they should redirect thisstupidcompany.com to www.thisstupidcompany.com not the other way around. All that said though that concept has kind of fallen by the wayside as it became increasingly apparent that most hosts exist primarily to host websites with other uses as secondary so it became the norm to just assume the www when navigating to the root domain.