But this just isn't the case. If something stays around after receiving SIGHUP, it was probably because that application intended to do so but it could also jus

But this just isn't the case. If something stays around after receiving SIGHUP, it was probably because that application intended to do so but it could also just be a hung up application that one way or another is going to stay around until it's killed. Sending a signal doesn't give you any sort of feedback to see if you're waiting for the application to close or if the application shouldn't be closed. Signals alone are insufficient.