Contra some other responses, I do think that was the intended design. However, I think it was a bad design, because it forces the desired behavior, rather than

Contra some other responses, I do think that was the intended design. However, I think it was a bad design, because it forces the desired behavior, rather than encouraging it. Stick the charge port on the side, so that it's awkward to use while plugged in, but not impossible. Now you've accomplished the same goal, without completely alienating everyone who has ever had the thing die while using it.