Because nobody's perfect…
If your handwriting is as bad as mine, it's not the end of the world with these unique pens.
I find them essential to avoid embarrassment for those once-in-a-blue-moon written tasks.
They work just as well as pencil and eraser and is ideal for that special youtube addicted young adult in your life.
Just a warning. If the paper gets hot from say leaving your notes in the car exposed to the sun. Your homework wont be there the next day. Wonder whether the lecturer/ teacher will believe that one. Cheap price though.