That is a shame as far as the Super Joey goes.
I can see why Dish didn't add the capability though. I'm sure it keeps their costs down some on the Joeys and you already have the ability to connect the OTA dongle to the Hopper. Since it's connected to the Hopper and the Joeys are integrated with the Hopper, you're able to see the OTA channels on the Joeys. Since you can view the OTA channels on the Joeys why would Dish feel the need to add the ability for an OTA dongle to be connected to it as well?
I get that we are super users and want the most tuners possible but it just doesn't matter to Dish. If Dish were going to allow any extra OTA dongles to connect I would assume they would just allow a 2nd at the Hopper.