I just don't understand!

I've never been married so it's hard for me to completely understand some of the "issues" that those close to me are going though in their relationship. However, I have been in a very long relationship, which included two kids, a cat (for a brief time), and many difficult situations. As we all know, that ended all too late. I should have done it months, if not years before I finally did it, but...lesson learned. And I think that's my point-- lesson LEARNED. I have married friends who constantly complain about their spouse. Most of the time it's just the normal wifely banter-- about her husband not cleaning up after himself or about her husband saying something moronic. BUT sometimes, my friends have a legitimate reason to gripe...and even question her desire (or lack thereof) to be married. Scenario 1: Wife is complaining about how she has to constantly do everything for her husband. I know there's a degree to relationships where we should WANT to do things for our partner, but there's also a point where we're almost enabling our partner to be an idiot. I mean, you're calling the doctor for your husband because he "doesn't know how" to do it? Seriously? You're running to the grocery store at 10pm because he "doesn't know" what groceries your family needs for the week? What happened to a grocery LIST for Pete's sake!? Really?! At this point, I just stopped feeling sorry for you and started being jealous of your husband! Please come shop for me and make my appointments for me! Please!? Scenario 2: Wife is always stuck at home. I remember what it was like to be a stay-at-home-mom. It was hard. Sure there were perks to being home all day in comfy clothes and such, but looking back, the majority of my memories during those three years as a SAHM include miserably waiting on Aaron to get home from work (or where ever), so I could have a freaking minute to myself! There came a point where I KNEW Aaron wasn't going to hurry home because he knew everything was taken care of. The kids were fed, the house was clean(ish), and things were as they should be. My heart aches for my friend going through this right now. It's unfair for her husband to expect her to stay home and tend to EVERYTHING, while he's ignoring her calls for help (literally, sometimes). Everyone needs a break. At what point does the wife take that final step to being completely single? I mean, her life with her kids will essentially go unchanged-- she already does everything for them. I, in no way, am suggesting that my married friends should throw in the towel. I know that relationships take work. A LOT OF WORK. And I am totally on board for that, trust me. But, at what point do we stop living miserably and start living the life that we WANT for yourself and for our children? People change. Even though we might not be the one changing, we can't stop our partner from changing. He might decide that the life he promised us wasn't exactly what HE envisioned for himself.