I really hate to contribute to further hijacking this thread from its true purpose but...
LesterOfPuppets answered TimothyH's challenge
almost perfectly. Somehow I've ended up with nothing but quill stem bikes and whenever I am trying a new bar or stem I simply leave the tape off while I ride as long as it takes to set everything up right. In fact, those are the only times I've used any of my gloves over the past few years.
Yeah, its pretty easy to change a handlebar or a threadless stem - but I find it even easier to just loosen the single top bolt on a quill and pull it out with its attached handlebar then pop in a different bar/stem combo whenever I want to change. I don't know about anyone else here but I use a different length stem on most of my different handlebars anyway, so this works great for me.
However, all that being said - when it comes to the "why would a modern bike maker use 1-1/8 headtubes and threadless forks on their retro-styled bikes" question...I have to say I pretty much agree with Richard from Wabi. Considering the additional stiffness of 31.8 handlebars and the exponentially increased number of bars and stems available in modern configuration, why would anyone do otherwise? Speaking as a user of quill stems exclusively - I can state from experience that finding just the right handlebars and stems for my 1" theaded bikes can become quite a chore...
I wish I had a Great Deal to link to get this thread back on track, but sorry - no such luck...