They've done it before.
My understanding is, it is legal to drive in from another entrance, although admittedly a bit more painful.
They are definately chewing up the tracks though , and there are some crazy drivers thrashing through the area.
I spoke to a 4WD trainer who uses the area to 'responsibly train' 4wd'rs and says its getting pretty dangerous.
The other issue is that users of the area are leaving a lot of rubbish in there. The old case of minority screwing it up for the others.
Its a wake up call for everyone using the area, that whatever you take in, you take home. They've got a couple of seriously ' very local' scouts who are starting to report back to various departments on misuse and littering offenders, with photos and number plates,, with hell fines to pay,,,, so take care..
The reason for the rocks across the other entrance was that it was causing dangerous conditions for 4wd's coming and going due to the proximity of the bend in the road just before that and short visibility. The other entrance is not far away.
ps let your tyres down, keep a safe speed, and be good to the local scouts.