Thinking in terms of how many words to write per day is harmful.
harmful? no, it's a good reality check, in an area that reality checks are hard to come by. Of course quantity isn't everything. However, people who think there is a vast chasm between quality and quantity are also wrong. Practice makes perfect, and the key to staying fresh is to produce fresh content. Ideas sometimes come seemingly through the keyboard, through the very act of writing. Ideas that you had not thought of, and had no idea were going to emerge from your brain. Sometimes, it's as if the act of writing actually creates the content out of thin air. Have you ever had that experience? I sure have, many times. That's why it's sometimes a good idea to make yourself produce something. Because maybe it will be crap, and maybe you will surprise yourself. You won't know until you stop typing and read over it.