And that's the one appeal of the A7/r - a very niche market of old lens users. There's very little in the system to appeal to the average buyer also looking at a Canon or Nikon full-frame DSLR. There's nothing mid-range or affordable in the native mount.
I dread all the on-line posts calling for Fujifilm to produce a full-frame X-series - can they not see what a disaster it would be to "do a Sony" and try and support too many systems?
I saw a guy with a Sony A7 mounted with an old manual lens on the tube one morning last week. Have to say it looked very cool but not sure I'd personally pay that much money to use manual focus all the time