Problem is Chris, that most of the people around at the moment weren't even aware of MMA back in the late 90's. The fact that the Colosseum was one of a handfull of MMA gyms back then (Colosseum, London Shoot, Lee Hasell's... any more?) is not importnant to them.
A gym can't survive on history (take the Lion's Den for instance.... who?), it is recognised by it's fighters now. How well they perform, how many fighters there are, etc.
If you look at Roughouse, it's a relatively new gym, 2-4 years old? Yet it has a packed stable of fighters at many levels, competiting on an almost weekly basis. Therefore recognised as a top gym.
Colosseum has 1-2 active fighters and no up and comers. Rushton is likely to stop fighting pretty soon, leaving Matt, who will be forced to look at other gyms, simply to keep his level going.
When you look at the Cartel, the gym that truly let the idea down was the Colosseum. The Colosseum ceased to attract and develop new fighters, whereas Quannum has a packed roster of up and coming fighters.
Personally I am on the cusp of ceasing to train at the Colosseum, simpy because the lack of commitment frustrates me and I want to continue to support Matt, wherever he trains.