We decided to add the screw terminal to the kit after the Capes had already gone through production. The original idea was that wires would just be soldered directly to the board.
Bottom line- though slightly less convenient to solder, it's supposed to be that way for now!
We're accumulating changes for the next revision of the Cape on our GitHub site here. There are several other things that are not as elegant as they could be with the board- eg, the power plug for the BeagleBone gets in the way of the second AWX PWM port, you can't see the servo header labels when servos are plugged in, and many people would like the high power PWM output to source power from an outside supply rather then the internal 12v regulator. If you come up with any ways you think we could make the Cape better, please let us know!
Thank you for the very descriptive photos, and good luck with your build!