N-channel switching is usually used for 'dumb' loads like lamps and motors. The N-channel devices are cheaper/smaller/lighter for the same power handling. (Electrons more mobile than holes in the semiconductor.)
It's not usually used for 'smart' loads like the Arduino. The reason is that the Arduino is connected to so many other things, many of which can provide alternative paths to ground. The Arduino won't be fully switched off if it still has a few buttons or switches connected to ground.
If you design the circuit properly, it can be done but for a one-off where you don't care if the transistor costs $1 more, it's easier to design with the switch on the positive lead from the battery.