You don't understand because you spend too much time worrying about a few empty seats rather than what happens on that bit of green in front of you. I suspect you will probably spend the first half counting empty seats rather than enjoying the football.
These threads are quite entertaining, the way some people seem to take it as a personal afront that a match isn't a sell-out. Everyone that wants to be there will probably be there, simple as. Just because we have a strong affiliation to BHA doens't mean everyone else in Sussex, let alone...