Quitting a job bears far less consequences than divorcing a husband. A job contract is usually transparent and serves as a legal document. You agree on terms and rules and if your employer breaks them you can sue him or her. In marriage/partnership, all depends on mutual trust that the other side will do as promised. And there's no transparency in reward for the work that is being done. Typically, there's no financial reward, therefore a stay at home partner has no money of their own.
Some women slave both as a workforce for society and for their husband who thinks it's beneath him to help with house chores.
It's always about people and their agreements, but also about the third side one can turn to if their rights were violated in some way.