Perhaps I am being a bit kind. I wasn't a season ticket holder when Hoddle was in charge, but I certainly remember the great atmosphere when Jol was in charge during the 2005/2006 season.
I'm not saying it's the sole reason for a decline in atmosphere, but I do wonder if todays ticket prices are a a factor in the decline in atmosphere. My season ticket has gone up by over £300 since the 2005/2006 season.
Obviously I think prices play a part but I'd say it more to do with a change of mentality. People have never before been feed so much information, and in doing so this information has altered their priorities. Previously fans would go to the game and it would be all about the atmosphere and the event of supporting your team. Now it's all about being entertained of putting your opinion first (e.g player x should play) because you feel your pricey ticket entitles you too this 'right'.