Werewolves don't write because they don't have any fingers. So that kind of puts a damper on things. Paws are cute and fun, so are claws (okay debatable), but neither work well with a keyboard or even a pen.
Ogres don't write because they tend to get easily frustrated. Then they smash the computer or eat the paper and well, it's a vicious cycle.
Only good witches write. I can tell because the other writers I've met are all way too nice to be secretly evil.
Writers don't write when they are down in the "dumps." When they've received their 458th rejection. When they think their first draft was embarrassing. When they get writer's block and don't know where to go next.
Writers don't write for lots of reasons. But the difference between Writers and demons, werewolves, ogres, and evil witches is that Writers persevere. They pump up the air conditioning when it's 113 or go to Starbucks. They find voice recognition software or just wait till the fool moon is over if they lose use of their fingers (not that this has ever happened to me). They remember to be nice because we're really all in this together.
They take a deep breath, send out a new query, dive into revisions, and start writing stream of consciousness or take a walk.
Or if all else fails they eat chocolate.
But Writers keep writing.