It's what keeps Twitter chirping, talkback talking and panel shows full of panelists. It fills Hansard with words and politicians with a sense of authority. And it keeps the national consciousness in half-baked thoughts.

For the most part we are happy to accept this. After all, no one has time for too many fully baked thoughts (and how many carbs would that involve?).

But sometimes, the rubbishy logic pile gets too high.

Excitement about Australia possibly joining the United States, Ireland, Canada, New Zealand and muma England in legalising same-sex marriage has been running hot this week, with the announcement of a cross-party bill.

Unless your name is Tony Abbott, who moved to downplay and dismiss any momentum.

"It is an important issue upon which decent people can differ," the Prime Minister said on Thursday.

He then noted it was "quite unusual" for private member's bills (which the cross-party bill will be) to be voted on and that the government was focused on national security and the economy.

(In other words, calm your same-sex marriage farm.)

When Abbott says that there are lots of different views when it comes to same-sex marriage, he is of course correct. But there are lots of different myths floating around about it, too.

To pick four of the big ones:

1. Other things are more important

Who could possibly argue that a wedding is more important than how many dollars, guns and Border Force personnel Australia has?

As Eric Abetz said this week, same-sex marriage is "way, way, way down the [priority] list".

But what this logic fails to acknowledge (apart from the importance of love and stuff), is that politics and parliaments routinely deal with more than one issue at a time. At a regular single party room meeting, MPs easily consider more than 10 bills. And multiple, diverse bills come before both chambers and get voted on in a single day of Parliament. It's called power walking and chewing sugar-free gum at the same time.

2. Same-sex marriage is a niche issue

Data released this week by the Australian Bureau of Statistics shows that 3 per cent of Australia's adult population, or about half a million people, identify as gay, lesbian, bisexual or another sexual orientation other than heterosexual.

So this is not an issue that affects anywhere near a majority of the population directly. But these half a million people have family and friends who also have a stake in it. And this argument ignores the surveys that repeatedly put support for same-sex marriage in the general community well above the 50 per cent mark.

But since when was politics just about what suited the majority? Politics – particularly in a democracy – is more nuanced than that. And can stretch to producing rights and progress for minorities.

3. It would be too weird for the government to consider a private member's bill

While it is certainly not de rigueur for the government of the day to consider any odd bill that a private member (non-frontbench MP) might produce, it is not impossible or unheard of. Even on big changes.

The lifting of the RU486 ban was put up by a cross-party private member's bill in 2006. In the 1920s compulsory voting (compulsory voting!) was introduced via a private member's number.

An important technical note here is that the PM himself said any same-sex bill before Parliament should be a cross-party one. If a government frontbencher is not going to sponsor it (which can't happen, given the Liberal Party's policy), then by definition it has to be a private member's bill.

4. What about the kids? 

A common focus of the same-sex marriage opponents – particularly the Australian Christian Lobby – is the children of gay couples. But while people can argue that children need a dad and a mum, same-sex couples are already allowed to have their own children. In the 2011 Census, 10 per cent of same-sex couples had children living with them. That horse has bolted.

More importantly, studies also show that kids raised in same-sex families are developing just fine – sometimes even better than their heterosexually parented peers.

As Australia approaches a vote on same-sex marriage, expect to hear more and more arguments about why it should not happen (like, what will Asia think!?) as opponents realise there is a serious prospect it will.

The real question in all this, however, is why shouldn't we just settle it? Why not simply have a debate in the Liberal Party room about a free vote – and if that is successful, then a vote in the Parliament?

If those in the anti-camp are so sure it's not a big issue and not many people care about it, what have they got to worry about?