If you were waiting for a CTA departure, then the delay at the holding point sounds like it would have been a "departure instruction" (ie H....) issue. Had this a few times over my life time. The issue is getting us separtated from the Class C guys over the top that are not on frequency. It's not the tower guys.
.....Yes, we still need to be mixed in with the new "CASA 6 in the circuit" regulation but this sounds more like the reason from what you have typed.
Probably should have mentioned this, but there was an aircraft waiting for an OCTA departure on center that didn't move either. It actually asked for clearance before I did. However you are quite right about the CTA departure delay. That has happened to me before too.