While some well spouses early on are tough cookies, some of them will snap not too far into their years of servitude, like a frozen green bean. Many of us who may have been tough and didn't snap, are no longer thus. No one really cares about us, just as no one is fond of mushy cookies. No one would choose a mushy cookie unless it was the last cookie in the world. Tough cookies might appeal to someone who likes to dip the cookie in a latte.
Well spouses are the mushy cookies of the world.
This is true of any household where one person's needs dominate, whether because that person must have extraordinary medical care or is just a take-charge, overbearing control freak. Reference a post of mine from a long time ago about a friend of mine who, after she got a divorce from a healthy, overbearing man, didn't know what to buy at the grocery store, because she didn't know any more what she liked. Her whole life had been about catering to his wants and needs. Ours get shoved aside. It's not a balanced situation.