I think, over time, the decline of clubs like Bury is inevitable. Their raison d'etre has gone. Back in the day, the only live footy on TV was the FA Cup Final. Most people worked until 12-00 on Saturday, so there wasn't time to go into Manchester even if you wanted to. Your live football fix was therefore your local team - Bury, Rochdale, Oldham etc. Now you can pretty much watch any match you like on TV/Computer. Young kids in particular like success so they tend to choose 'big' teams so they can bathe in reflected glory. Nothing new in that, it's just easier to watch the matches now.
The people who still watch the likes of Rochdale are the true, grass-roots football fans and don't care about being part of something 'bigger'. However, my guess is their numbers will decline over time. We get so much exposure to top-quality football these days that paying to watch Bert Scroggins boot the ball into Row Z is less attractive than it used to be.