Because this worked so well for DTM
Things is,Supercars was originally a production car championship. Normal cars through to the Group A era.
From the V8 Supercars era it were still at least close to hotted up sport sedans. I'd welcome a return to more production based racers. At least until they get a hold of where this series is going.
Yes, the whole point are racing cars no-one else race. However, it just continuously looks bad, because no-one outside Australia want to join. Why is that?
When the heads of the series stop chopping and changing and be sensible to really wanting others to participate, the series is in no man's land. Car of The Future was great until they started hanging the rules to suit the Holden and Ford engines. Nissan were back, AMG/HWA joined, Volvo joined.
Anyway, GT4 isn't going to happen because ARG run that series. Supercars only allow Touring Car Masters on their bill. Supercars didn't want TCR participating and it's not a rival series. And as for the Super 2 and Super 3 feeder series, those, according to Roland Dane, are in jeopardy due to track time for the hose entrants.
Me, personally, what I saw at Newcastle was good. However, that's not translating to what he teams are experiencing.