It's not the DOCSIS standard, it's the providers that's holding it back.
Everybody here thinks it's a joke, unfortunately it's not. http://abbottsinternet.com.au/
For this I currently pay about $75 per month. Sigh.
The government needs to re-negotiate it's deal with Telstra, and I expect the HFC network remaining with Telstra as a wholesaler monopoly will be a part of that.
No-one has said they're going to "rip up" the HFC cable. It was to be decommissioned under the old NBN plan and it's future hasn't been decided under the new.