Could you go here:
http://www.european-football-statistics.co.uk/englandcontent.htm
And find me an example of any club that has had significant attendance drop-off in top flight for the last 20 years?
The best examples that I can find are those that are nailed on for relegation - between 1-2k...
They're basing it off football as it was 35 years ago.
Can't think of anything more stupid than to suggest support will significantly tail off if we manage to stay up for a few seasons, absolute madness.