Why hasnt a turntable manufacturer produced a table with automatic tonearm return/shutoff?

I'm listening to my old Technics 1700 turntable, which has the tonearm return/ shutoff mechanism. It's one of the reasons I don't upgrade. The idea that you have to get up to retrieve the cartridge and turn off the machine makes little sense when the technology has been there for years. I know the issue of the mechanism introducing sound into the table, but it seems to me that the mechanism can be isolated and kept off until the record ends. What gives?