I'm in no way an authority on these things and (correct me if I'm wrong) the whole custom overbuilt, beefy liner/frame lock thing is kind of a fad. Maybe not very many people really want a custom lock back? If I built a big custom knife it wouldn't be a lock back. I've also always thought the lock back was a good way to put a sturdy lock in a thin knife whatever as if you put a big thick liner in there it wouldn't be to thin and if you gonna make a big thick knife why not use the already beefy liners? Idk, just my thoughts.