I'm not a Bleriot hater and don't criticize Rivendell for introducing it. What ticks me off is that they quit making the Rambo at the same time, so cyclists were forced to go the 650b route if they wanted a Rivendell. Although 650b wheels might be the greatest thing since sliced bread, they are not for everyone. In my case, I have 3 other road bikes with 700c wheels and tires and did not want an oddball bike with components that would not be interchangeable. In other words, if a spoke breaks on my commuter bike, I like being able to grab a wheel off another bike until I can get it fixed. Also, the roads are generally very good where I ride, so I have no need for a fat tired, cushy ride. We also have a lot of hills in NC, so light weight is a high priority. Finally, you may be able to find 650b wheels and tires if you shop around on the internet, but they are not readily available and even Rivendell didn't start offering built wheels on their website until recently.
Anyway, the Rambouillet was a great frame, and currently nobody else seems to make a frame just like it (except for some of the British bike companies like Mercian and Bob Jackson). Why Rivendell decided to ditch that frame is a mystery to me, but I suspect it was because they were trying to "push" people to buy their 650b models. No thanks.