Thanks, Canali!
Honestly, I see no harm in what Rivendell's doing. They make somewhat quirky bikes that some people really like to ride, and that's a good thing!
I may not be sold on the superiority of threaded stems, but on some of the frames they've started supporting threadless. As far as versatility goes, it's easy to get a converter to go from threaded to threadless.
As a side note, I'm spec'ing out a Bleriot build for myself. After years of dealing with frame geometry compromises to fit 700C tires, I'm ready for something that doesn't crack at the head tube due to a ridiculous angle or have a wheel hitting my toes. Smaller frames with 700C also don't seem to fit a lot of other standard components like racks (the sort that attach to the brakes) and fenders. The LHT uses 26", but my riding style doesn't require something THAT sturdy. I looked at 650C bikes, but those are even more restricted by being exclusively racing bikes. Taller riders might not see a reason for a nonstandard wheel size like 650B, but smaller riders like me tend to be pretty happy that someone helped popularize a viable alternative to 700C.
Also, I'm going to LOVE putting my set of mismatched Ultegra brifters on it. It feels so naughty that it's oh so nice.