How many threads claiming women need to be married to be “protected”. More than I can count
That somewhat deliberately oversimplifies it .
People advocate marriage in situations where a woman is choosing to give up her job and financial security to stay at home precisely because operating the man as breadwinner and woman stays home model is risky for women and the contract of marriage ensures the woman's contribution to the household is valued in the event of a split.
A woman giving up her financial security to a DP is in a terribly risky position. She loses her income, job/career, employability prospects and future earnings due to time out, she has no national insurance contributions, doesn't have a personal pension in most situations.
Should the relationship go downhill, the woman has limited ability to leave because she may not be able to set up on her own due to limited personal funds. Depending on how they structure their finances (which is almost always in favour of the man in these situations) in the event of a split the woman ends up with nothing.
Nobody says all women should be married to be protected. There are many situations where being married offers very little in terms of short term protection if both people are similar earners, have all assets I joint names, appropriate pension arrangement etc. There's also ways for couples to legally arrange affairs etc without marriage and this is often done if they wish to protect inheritance for their DC if it's a second long term partnership.
What is advocated is that women make informed decisions and don't get railroaded or drift into situations that are against their best interests. Sadly on MN there's still a lot of women who insist on having an issue with this and so perpetuate the same lies that some men trot out e.g. "marriage is just a piece of paper, we have children and that's a bigger commitment, marriage isn't very feminist so you're actually more empowered to be an unmarried SAHP, we don't need a party to prove how much we love each other, ignore the smug marrieds they think they're better than everyone". These are all arguments used by some to mislead women by pretending that it's somehow unfeminist to suggest marriage is a legal contract that affords certain protections and obligations (despite countless threads of women who've given everything up for their DP and find themselves shafted 5/10 years later).