Why do people draw, paint, cook, garden, make jewelry, sew clothing, knit, crochet, play card games, throw pots, sing in the shower, dance, play racquetball, ride their bike, birdwatch, hike, swim, go camping, play the guitar... when they aren't going to do it professionally? When they will not earn a single red cent, and in fact may spend quite a bit

That, right there, is the thing I realized some years back that entirely changed my attitude about fanfic.

I was doing things as hobbies I never planned to make a penny off of, things that I wanted to be hobbies, never mind who else makes a career of them.

Why shouldn't writing fill the exact same role for someone else that my hobbies did for me?