There's a handful but it's a niche within a niche market, so there's not much profit in making one.
I wouldn't say the blade availability is the reason though, the limited options actually make it easier, and the PTFE blades are more than acceptable and equal the best AC and DE blades in finish for me.
I would say its probably the design itself. Being deeper from rear to cutting edge it limits the head design and I would hazard a guess that some think it isn't as easy or convenient to get a close shave.