I have no problem with students who are slow learners and who are happy to put in the time and money, as long as I know they can make safe pilots in the end. It does nobody any favours to keep someone going who is never going to make it or, worse, might just get it together on the day enough to fool an examiner into passing him or her but who is going to be a danger to themselves and others. We all have a duty here - you can't just say that the exam pass is all that's required because that's the standard.