Clearly there are many reasons for cohabiting rather than marrying. In my own case, one of the most significant reasons is a strong desire to avoid giving my partner any claim on my assets. Another reason is reluctance to unite myself any further with a man who is consistently unwilling to contribute in even the smallest way either to the financial or practical running of a home and family.
During the 3 years we have cohabited (the last two of which have been with our small daughter), I have:
Paid the mortgage
Paid the bills
Worked virtually full time
Paid for and managed all childcare
Taken care of the baby
Paid for all baby-related items
Cleaned and managed the house
He has:
Not worked a single paid day
Not sought employment
Helped out with perhaps 5% of childcare
Lived off money from his parents
I have had a wonderful daughter with a completely unsuitable man. That is my personal blessing and curse. I live with it, and try to ensure that we all enjoy family life. However, I would be incensed if I thought that my parasitic boyfriend might end up earning any more from our current situation than the simple joy of living with his daughter.
Following the rulings on Miller and Macfarlane there will certainly be many who choose cohabitation over marriage precisely to avoid the division of assets. I believe as strongly as anyone, that good cohabitation is just as loving, secure and consensual as good marriage. However, it is naive not to think that in many cases cohabitation does signal a reluctance on one or both sides to commit fully, whether for emotional, financial or other reasons.
The best that legislation can do then is to make sure that cohabitees are well-informed and able to opt INTO the same rights as married people. Otherwise, those of us who choose not to marry will have nowhere else to go.