Because people who support the club by buying season tickets deserve a chance to get a ticket before fans or part time fans who only turn up for big games. The club got it very badly wrong for a game at Liverpool a few seasons ago when supporters who had season tickets and went to every home game and quite a few away lost out and couldnt go. Since then they have tried to prevent a recurrance. The problem here is the lack of time to sort anything out - Not the clubs fault