Caley had average crowds of 3000+ in the 1950s and 60s? I'd doubt that, if only because I doubt that there is reliable verficiation for crowd figures. Back in those days many teams got huge crowds, junior games in Glasgow used to get 30,000. Things have changed for all clubs.
I thought that the away stand held 2,200. That means 5,500 spaces for home fans, so maybe an extra 2,000 odd show for the Old Firm games. People want to go to the 'glamour' games I suppose, fans who have to pick and choose games due to work or family concerns might also want to see the 'big' games.
One thing I think is important is that the fans who turn out for these games are hugely important for the club - they are the people we need to attract to more matches, they are potentially regular fans but for whatever reason don't make it to more games. A haughty attitude isn't going to encourage anyone to make more of an effort to get to the home games.