Its far more complex than that.
The Force IP was purchased this time last year, effectively putting the team in the hands of the ARU.
The Brumbies, Tahs and Reds were never considered for culling, it was only the Rebels and the Force - why?
The Rebels were to Cox by the ARU in 2015 - why?
When the Force were able to buy back their IP, it was refused - why?
I agree that it wasnt a desire to screw over the Force, rather, it was self interest by ARU board members to protect their own back yard that resulted in the Force being the ones dumped. And it was a series of events that lead to it that suggest there is corruption within the ARU.
Hmmm ... I think corruption is a bit of a strong accusation. Incompetence, perhaps. Clear focus on NSW and Qld, of course.
Clearly, they have had some sort of view that they wanted the Rebels to be privately owned. It failed once but they were so committed to the idea (maybe because that is how they want to progress with all teams. So when the opportunity came up again, they made the move again.
There was also a massive increase in broadcast revenue when moving to 18 teams and I don't think anyone really thought that they would be cutting teams in 2 years.
In terms of the Tahs and Reds, there is no chance that they would ever be on the chopping block. You can argue whether this is from the ARU's focus on the two states or because they have historically and currently produced most of the national team but they are always going to be untouchable.
So that leaves the Brumbies who have been Australia's best performing team albeit in a small city. Realistically, they probably should have been considered. The crowds there are as bad as the Rebels and Force and they have a much longer history of winning games. Both the Rebels and Force have had a pretty poor history of performance which would have contributed to the loss in crowds - no fun watching your team continually suck
If the Force were seeing crowds in the early days (in the 20,000's or at least high teens) and the Brumbies were seeing their current crowds, then I think there would have been much more pressure put on the Brumbies. But current crowds for the Force suck (as they do for all teams).
If the Force survive, then I bloody hope that the missing crowds from previous years turn up. The large crowds of upset Perth and Melbourne Rugby fans didn't exactly turn up on mass when the teams were under threat.