I dont know about counter-productive. Inefficient, almost certainly - but not counter-productive! Think of all the stuff you will learn!
I've had a couple of ideas for tasks. The initial one that I came up with (which won't be used, so I will tell you as an example) is:
Turn on a light when a button is pressed.
The obvious solution is to use a pushbutton and LED straight into the Arduino. There are an infinite number of other solutions, though (turning on your porch light when a key on your piano is pressed, for example). Those are the solutions that this challenge is looking for!