It's ok to trace. Really.
But I'm beginning to see the light (no pun intended). Sometimes tracing just makes sense, especially if you are drawing something architectural. The building lines can get very confusing among all the grid lines!
I have traced my landscape drawings because the lines are quite simple. I don't need the aid of a grid to get the skeleton of the drawing, and the interest of the piece develops with the shading and color shifts.
Don't have a light box? I use my patio door with the morning sun behind it. Here Cecelia Novak places her paper on her Ipad, and wha-la! A ready-made light box! Just download the Lightbox Trace app to get started.