I don't care much either way, except that I see some cases where using a 'www' hostname can be advantageous. In television and commercials, it's a useful marker that what being listed refers to a website. To the layman who is not familiar with all TLDs, 'example.nu' may be bogus, while 'www.example.nu' is immediately recognizable as referring to a website.
My take: 'www' helps in disambiguation, and sure is nicer than having to prefix all names with 'http://.
Why is it horrendous? The string is concise, unambiguous, and works when you put it in the location bar. Including the scheme makes sense only when there is a risk of ambiguity, and even Tim Berners-Lee admits that exposing such a technical detail to users wasn't the best design decision.
I believe he said horrendous since there is a certain trend that Facebook will, in some sense, be a closed internet. There may come a time when not being a Facebook user means that you cannot see some significant portion of the Web.
Well for facebook.com/productname that means a commercial decision - is it worth excluding a (probably) significant portion of the internet from viewing our product's site.
Why exclusion? FB Pages are public by default, no login required. Some individuals' comments may be invisible due to their privacy settings, but technically non-members are not excluded per se.
My take: 'www' helps in disambiguation, and sure is nicer than having to prefix all names with 'http://.