Why still manual lenses?

You are kidding me!  Leica lenses are manual because it is a rangefinder camera (mainly, although not always, bought by pseuds).
Yes, it is harder to make an AF lens, which is why most of the one-man-and-dog specialist lens makers are stuck making MF one, and why most people, me included, have minimal interest in them.
I've been using SLRs for forty years, and I want results, not nostalgic toys.

--
www.flickr.com/photos/acam http://thegentlemansnapper.blogspot.com