They could have simply provided a standard USB-A port. Trying to put all possible connectors on the thing sounds like a fools errand, regardless of Apple's stance.
If you look on their kickstarter page, they actually did provide USB-A ports on the bottom of the unit. They just weren't able to 'compromise their product', which makes me believe that perhaps they had other underlying issues, unrelated to Apple's licensing.
There are already a glut of portable chargers on the market that provide a standard USB-A port. The point of this device was to stand out by providing the Lightning (and other) connectors without needing additional cables.