Horse 1605 - Why Do We Still Have Five Cent Coins?

In economics there's a thing called the "denomination effect" and that's where there is a greater preference for people to spend coins over notes and to spend smaller banknotes over larger ones. People have a psychological stop when it comes to breaking up a larger note.
Then there's the issue that ATMs spit out Fifties and Twenties; so if you ever get a Budgie (a One Hundred), no-one really wants to accept it because they won't have the change.

Anyway, on to five cent coins... WHY DO WE STILL HAVE THEM?

- Cute but pointless

The current five cent coin which was introduced in 1966 was a direct replacement for the sixpence. The sixpence along with the shilling and what would become the florin, have a planchet size which was set in 1816. If you allow a conservative measure for inflation, the sixpence of 1816 bought the equivalent of $17 now.
It's not like we have an emotional attachment to them either. It's "Something old, something new, something borrowed, something blue, and a silver sixpence in her shoe", not the decimal equivalent. If a bride found a five cent coin under her heel she'd "grab the dainty shoe, and quickly flush it down the loo". Noddy was always pleased when the people of Toytown gave him "a whole sixpence" as a fare for a ride in his little red and yellow taxi but I'd suspect that if he was given five cents now, that the Clockwork Mouse and Miss Harriet the Pink Cat would be left standing on the kerbside.

Even if you have twenty of the little space suckers in your wallet, it's still not like they're useful for anything. Maybe you can buy a Mars bar but only if they happen to be on special at the time. This perfectly illustrates that the five cent fails at its only function which is to be a useful store of wealth in the flow of goods and services.
People will only stop and pick them up about half the time. I suspect that most people who do are hoping that it's a two dollar coin, only to be disappointed by the sleepy echidna staring lazily off into the distance.
To make matters worse, train station vending machines don't accept them. Coles self-serve checkouts don't accept them and parking meters don't accept them. If even automated devices don't take them, then what is the justification for their continued existence?
This is the idiotic thing - in 2012 they made 18 million of them; in 2011 they made 44 million, 2010 - 59 million, 2009 - 83 million and in 2008 more than 200 million of them were spat out of the Royal Australian Mint. Why? For something that if it completely disappeared tomorrow and we wouldn't miss, then why are we spending any effort on them at all?

Okay, quite apart from the issue that all of the coins are too massive for their function (we should just copy New Zealand here - their coins are made in Canberra anyway), the five cent coin currently serves no other purpose than to get in my way. New Zealand sensibly got rid of its five cent coins in 2006. How come we in Australia can't?

Why are we still holding on to coins which served a purpose two centuries ago but are as useful now as an ashtray on a motorbike?
Sheer utter pointlessness.