I'm a part of the sane part of the world :) But it's more practical because if you know the Wh of a battery and you know the wattage of a power brick (simply V*

I'm a part of the sane part of the world :) But it's more practical because if you know the Wh of a battery and you know the wattage of a power brick (simply V*I), you can quickly calculate the number of hours it will take to charge the battery from 0 to 100. Knowing the number of seconds isn't very useful to humans because battery charging is usually in the order of hours. Of course, machines should always use Joules internally.