This post arose from trying to work out a commuter bike build on paper. It would have had 650B slick tires in a 26" disk frame - since 38's on 650B are about the same diameter as 50's on 26", and there's no brake reach issue with disks. All the 650B disk wheels I'm finding are tubeless. So I thought maybe it would be fun to try tubeless, but I can't find tubeless-ready slicks. Why not?
So a few years ago when I set out to be a bike nerd, 650B was a twee affectation by Rivendell and Compass and a few others. They stressed its convenient size to mount big tires and fenders, while maintaining a conventional road bike geometry. They apologized for the lack of tire choices, and tried to provide premium options. At the same time, tubeless tires for mountain bikes came about. The supposed advantages are light weight, better ride via low pressure, higher reliability. As a result of this we have plenty of options to try tubeless conversions on a commuter bike. Stan's No-Tubes kits are available for 26" mountain and 29er and cyclocross, which probably covers most things that are not high pressure road tires; and if you want to you can do the "ghetto" conversion for even cheaper. Since then, purpose-made road and mountain tubeless tires have become popular.
But there's still no design-specific commuter tubeless rim/tire that I can find. There's no big tubeless-specific slick to put on those 650B tubeless wheel sets, or 26" or 29er for that matter. There's no big road tubeless tires to run at lower pressure. All the 650B slicks are clinchers.
Wouldn't we of all people want the supposed advantages of these things? Whether or not they really are advantages, wouldn't the marketers be aiming for the mass market?