Thing is, they haven't really. It's just that for the big clubs the habit now is of going once or twice a season rather than every week. Football is like the theatre or a nice restaurant - something to do on occasion rather than a regular weekly ritual. Which is a shame, because it fucks it up...
That would average out at £90 a game, which is over double the amount a category B game match-by-match price is for the cheapest seats (according to the OP), so I'm not sure if I believe you!