We'll never know - what we do know is that in both AFL and soccer, that the establishment of a 2nd Sydney team in the west has seen support at corporate and fan level grow.
Most of the Waratah's woes were self-inflicted by the board and the coaches they appointed.
Ok.
So let's ignore the Giants. Why?
Because in 2015 they averaged 10k attendance which is less than the force and were founded on huge capital injection by the AFL and huge draft concessions.
Most proponents of the force argue if the ARU had been able to provide that type of support they'd be in a much better position.
The Wanderers average 12k at every home game. Basically the same as the Force, but were initially very successful. In their first season Sydney FC had their average attendance spike at 18k but it has since dropped slightly each year down to the low 17ks basically on par with their first ever season.
So the Giants pull less fans, the Wanderers only pull the same amount despite quite a bit of initial success and over time after an initial spike, Sydney FC have dropped to their first year levels.
The swans saw their average attendance drop by 5k the year before the Giants entered the comp. This was despite their climb from 12th in 2009 to finish 5th and 6th in the next 2 seasons. In the Giants first year they finished 1st, won the Grand Final and were still down on average attendance prior to GWS.
Their average attendance in 2015 was 700 higher than 2010.
So the swans have definitely seen an impact.
Then there's the other considerations.
If there was a Western Sydney team, would they play at Homebush? If so would the stadium have offered the same incentives for Waratahs games. The team made $400k in 2014. Take out the crowds from 2 Homebush semis and incentives for their Brumbies and Crusaders games and it's probably closer to a $400k loss.