now that i think of it. this thread is a little confusing. If are you actually doing a survey then thats fine
But it sounds like you are looking for other people to come up with good excuses, for why your PhD might not be working out, so that you don't get your ass kicked by your sup. If this is the case, you are wasting your time and I doubt your supervisor will take generic excuses you pulled from the net as justification for lack of progress. Do you not have any idea yourself why a PhD might not work out?