Trying to imagine the most charitable interpretation here: Perhaps they're worried about people breaking the charge-port, where standard USB connectors are not

Trying to imagine the most charitable interpretation here: Perhaps they're worried about people breaking the charge-port, where standard USB connectors are not rated for the kind of wiggling and jiggling going on. Especially if some portion of consumers always leave it connected, either out of ignorance or paranoia. From that perspective, placing it at the bottom is a clever way to ensure that the more-fragile connector is left alone while inserted.