But Hoskins hit back in an open letter, accusing the critics of having an agenda.
“Not one of those players selected himself and yet there are those who wish them ill, and even to fail, as some form of protest against rugby and what they perceive to be our transformation record,” he said.
“Many opinions have been aired over recent weeks and I have listened to them with growing frustration.
“I have been frustrated because the good story we have been telling has been falling on deaf ears; and we do have a good news story to tell.
“Let us get one thing absolutely clear: Our sport is massively transformed from where it was in 1992.
“The idea of an ‘exclusive’, ‘white-dominated’ game is frankly laughable.”
South Africa has made strides since Chester Williams broke the race ceiling as the only non-white player in the 1995 World Cup-winning team.
But SARU’s goal of having non-white players make up half the national squad by 2019 seems remote.
Promising young black players often face tough hurdles, with most township schools lacking finances, facilities and specialised coaching to nurture their talent.
Many schools in overwhelmingly black provinces don’t offer the sport, which is more widely played in the Western and Eastern Cape provinces, home to large Afrikaans-speaking white and mixed-race communities.
Hoskins admitted to the disparities in participation rates but said he was confident SARU could achieve its targets.
“Our game thirsts for outstanding players and whether one emerges in a township school or from a traditional rugby school you can be sure the system will find him and nurture him,” he said.
“The transformation train has left the station and it is the critics that have been left on the platform. Rugby is definitely on track.”
The World Cup squad flies to London on Friday and Hoskins urged fans to show their support ahead of their opening match against Japan in Brighton on Sept. 19.
“I would urge all supporters to demonstrate their true feelings towards the team, in the way that the team shows its loyalty to our country — by wearing their Springbok jerseys to the shop, the office, the factory, the mine or on the farm on Friday,” he added.
(Reporting by Ian Ransom in Melbourne; Editing by Amlan Chakraborty)