Why Debian is not Ubuntu and vice versa

Reading the arch Linux newsletter (http://www.archlinux.org/static/newsletters/newsletter-2008-Aug-04.html) and talking to some of my friends. I was noticing that many people now see ubuntu as debian, they are now seen as one thing. Many people that complain about ubuntu could just run debian. It has been quite a long time since I had a debian install but I think you can even install it without X. So if you don't want the bloated windows copy, that ubuntu is, but you still like the pakages why not install debian. Ubuntu might be using debian as a base source of packages but please don't say

(As of this writing, I'm still unaware of any bloat-free editions of Ubuntu.)

beacuse that is debian.