Only you can really know whether a) you need to be at home for your family in your circumstances and b) whether you have the social group /hobbies/passions to allow you to live a fulfilling life without work.
I reckon I could easily fill my time if I gave up work. There's loads of things I want to do and achieve. I dont understand the 'how would you fill your time' arguments. 
That said, I am very reluctant to lose my pension contributions and long term security so wouldn't be giving up work unless DH was willing to pay into a pension pot for me as well. Even with the legal protection of marriage, it's important to make an informed decision and take personal responsibility.
I think where issues arise is when some women don't set themselves up with the potential to be financially independent, give up work and associated NI/ pension contributions, aren't married and then find themselves very financially vulnerable.
For example, I find this attitude hard to comprehend:
I think there's a lot of lucky mumsnetters who have great jobs that they love and are in a loving, supportive relationship with a man (or woman) who shares 50/50 of all the wifework and households tasks
It's not luck that got me a career I enjoy and a husband who does his share.
Planning, working hard, giving up a job to retrain, DP (Now Dh) supporting me to retrain and holding the fort, choosing a man that believes in equality, choosing a man who believes as an adult he is responsible for the house as much as me, choosing to financially plan for our future, discussing hypothetical shared parental leave before getting married etc has put us in that situation.
I can't stand the idea that some women claim it's luck. It's not. It's hard work and choosing someone who views me as his equal.