I suppose the reason they have not got rid of this weird final foot format conversion step is all to do with backwards compatibility or reusing old designs for the kit or something?
It's not really so weird it's pretty common among cable companies the world over to use this architecture now. It means what goes through the wall and into the home is the same as the hybrid areas. Again, I would recommend reviewing the video I mentioned along with information on newer cable access network evolutions such as Remote PHY, Remote MAC-PHY and D-CCAP.