Sure, but that's custom and correlation. There's no cause and effect proved there.
Early on, most servers were set up such that you had to have a www because that was what mapped to the public, web-accessible document root for the webserver. But that's convention.
Let's see I have a hunch.
Amazon.com - English
Wikipedia.org - English
youtube.com - English
google.com - English
What have I learned about what Google likes?