I put it down to tv as much as anything Gary. When I were lad growing up in the late 60s/early 70s the only top flight football I got to see was on The Big Match on a Sunday afternoon when you'd get the highlights from a max of 3 games just over 24 hours after the event. If I was really lucky I was occasionally allowed to stay up late on a Saturday night for Match of the Day where you got highlights of 2 games (max of 20 mins each). I'm guessing that if you then go back a further ten years, to the days when Tooting Terrors were at their height, it was  even less than that.

Compare  that to what happens today. Kids can watch 2 or 3 Premier League games in their entirety, live, virtually every week and see the highlights of every single game played, virtually on demand. For me, watching a top flight game live was a once a year birthday treat when my Dad would take me to see my team, Everton, playing at one of the London sides. Other than that if I wanted to watch a game of footy live or in its entirety then me and my mate would wander down to the local rec to watch Frimley playing in the Surrey Intermediate League

Tim is absolutely right about the amount of top class football you see on TV affecting gates, but there are other considerations. A lot of men worked on Saturday mornings and then went straight to local football in the afternoons. They certainly didn't go shopping with their wives. Also there weren't many cars around in those days. After the Forest match I was collected by somebody who worked with my father (he was on business in Africa) who parked right outside the ground. As a 10 year old, my father thought I might have trouble trying to get home to Carshalton on the bus, with 16000 other people around.
Great days and great memories.

Might have Lyn Catchpole panicking too as I believe that's around three times the official stadium capacity!