There's a thesis to be written on how they burned the goodwill towards the team that existed when the golden generation started to leave in the mid 2000s. In short I think they got a bit complacent (expecting that Canberra would always support them) and took their dominance over the Raiders as a given. People pretend a new stadium in the city would help but that's BS, the local public servants have voted with their feet and it would take a huge hiccup from the Raiders to turn the tide.
I think this is closer to the truth. I think people got sick of the power games and BS that went with the team. From property to boardroom issues, it has been stipped of so much. The "clique" running it have done it no favours.
But it's also become a victim of its own arrogance and lack of commercial ability. It's burnt sponsors and even simple things like having preseason games out of Canberra then during business hours at a private school- no way you will ever get new supporters let alone keep in touch with your local support base doing such stupid things. But they seem not to either get it or care. I think it's just the insular thinking that is inherent in Union. It now just chasing any quick dollars to keep the the dying dream on life support a bit longer. Crowds and entertainment are an afterthought. Sponsors don't care as nobody is watching.
Add on to that they are simple not inspiring nor exciting anymore. Burnie just brings the same-same mediocrity. Where is the variety in coaching or game play? We always seem to recycle past players and and make them coach and expect to get results. Frustratingly they always seem full of potential yet never good enough. Always a should of / could of with the Brumbies of late. They simply have very little appeal. Even their own faithful are slowly dropping off.
But it's not all the Brumbies. It's the shite flash-in-the pan competition that's run poorly. Which ever idiot that thinks that 7 home games will generate a supporter base for a team each year, let alone support that a code needs to take a hard look in the mirror.