Consider my feathers ruffled!
I pay top dollar to fly business class on domestic and international QF and it's always a disappointment to enter the business lounge and find it chock full of people. Now I have to queue up with them too? Ugh. As a recently-demoted WP, I've done my fair share of Flounging, but when there, I couldn't help thinking that I would be pretty annoyed to have paid $20k or whatever for a first class ticket and have to share the Flounge with the likes of me!
Personally I think that if QF wants to let non-business people into business checkin and lounges, don't call them business checkin lounges! Call them something else! The same goes for the Flounge. It's not an Flounge if they let people like me in!
I can see why QF does it - it's a form of upgrade that costs them very little, but unfortunately it pushes the cost onto other customers in the form of queue times and crowding in the lounge. This means that the QF Int J experience is not consistent: one minute you are in a lounge where you are expected to scoop out your own runny scrambled eggs from a big bowl then find a seat in a zoo of people, then the next minute you are in the aircraft where they are serving you in a hushed environment with white linen tablecloths. I have more personal space on the aircraft than on the ground.
If I were running the show (flying spaghetti monster forbid!), I'd align the checkin and lounges to the class of travel, so that you get the same standard of service in the air and on the ground. I'd reward WPs etc with the occasional complete upgrade (i.e. upgraded checkin, lounge and flight) rather than a continuous half-upgrade (upgraded checkin and lounge, but not flight) that impacts other passengers.
Having said that, if QF is silly enough to let me into the Flounge, I'm gonna go!