If I remember rightly, before the 80s, in Australia there were no rights conferred to ‘common law’ relationships. At all. The De Facto laws came into being with the decline of popularity for marriage and the increase of living together becoming an option with out the stigma.
Remember in the 80s in Australia, there was a lot of stigma in some families about ‘living together’. Many families would refuse to accept de facto partners rights.
I have seen the both the pros and cons of this law actually. It does make people who decide to cohabitate make a conscious choice after a while, because it is not a new law, most people are now aware of the repercussions. There are less ‘trapped’ now that it has been in for so long. If not, then definitely an awareness campaign needs to be done to make sure people realise there is a legal implication to the arrangement. And it needs to be a conscious choice
For a period of time even after it came in, military people still had to get married to claim entitlements (such as living arrangements and moving allowances etc). It was only maybe mid 90s de facto relationships were treated equally in the forces. I think it was similar in other occupations where to keep you job you had to move where you were sent including teachers, police etc (there may be more flexibility offered now but there was none in the 80s).
It works well when the relationship ends acrimoniously or is abusive. And of course, there needs to be proof of the relationship.
It also takes into consideration superannuation which also become a guaranteed right in the 80s. (The government at the time told my generation not to expect a government pension as we needed to provide for ourselves through this compulsory super with our own contributions effectively).
Of course, splitting of assets is based on how long a couple have been together etc. just like a divorce. There is a lot of fear spread about it being 50/50 straight away but it has not been the case in the states I have lived in.
I have also seen it work when no wills have been left and the deceased family refuse to acknowledge the relationship. Even today, with the family siding with an ex and ignoring the partner of the last decade. Even for next of kin decisions in those situations.
I get the ‘forced decision’ argument, but having grown up with the law in place, I also have seen situations where it offers protection. I would also think there is now enough knowledge of the law domestically that people now work with it. I know my nieces recently have had to rely on the protections the laws offer while ‘saving up’ for their dream weddings, that keep being moved after the babies have been born, Because in their cases those glamour weddings are like a prize 
and no advice to the contrary was welcome.
Conversely, there are contracts (Binding Financial Agreement) where couples can consciously state how they want assets and finances to be treated at the time the relationship finishes. But, I don’t have any experience with them. I am sure there are plenty who can discuss if and how they work.
So, yes. You can move in together and still protect your assets and pension etc. It just means that is then the conscious decision you make, if you see what I mean.
Like any law though, if it is no longer applicable or it works in a way that undermines the intention, it needs changing to suit the current needs of the population.