Just another possible reason for an ubuntu preference: I've just been trying to find out how to get my new bluetooth keyboard to be automagically connected at boot time. Naturally, I turned to google, and all the top hits I got were (mostly pretty informative) pages from either ubuntu or gentoo web sites. I have had this same experience on different searches many times before. I can imagine folks who constantly find descriptions of how to solve their problems on ubuntu web pages might at some point be tempted to just go ahead and run ubuntu so they don't have to track down any differences between the distros in order to follow the advice. Of course they might get the same idea about gentoo, but comparing the install process of gentoo and ubuntu would send most folks screaming to ubuntu every time :-).
