At the time they believed that Matt King, Mark Gasnier, Timana Tahu and (yes) Eric Grothe Junior were and would be superior to Greg Inglis. There was a lot of talk about how Inglis was too young for Origin, how the selection would backfire on Queensland, and how the NSW backline (and team in general) were so far superior to what Queensland were going to deploy that it wasn't even funny.
Hindsight has proven those notions hilariously wrong, but it was the perception at the time.
Inglis wouldn't have played that year for NSW, and may only have been considered for the Blues the following year, and/or after King, Gasnier, Tahu, and Groethe left the game.