I used to work f/t and am now a SAHM/student. I gave up f/t as neither DD or me appreciated leaving her in nursery 8-5 everyday, she wouldn't settle and I decided that I had years yet to have my career.. I found SAH a very hard adjustment, at first, but now love it and feel a sense of freedom.
I have couple friends who both work, most of them have one whom works part time or they work around each other, or use nursery part time. They drive pretty ordinary cars etc etc and are not wealthy as their lifestyle/house has gone up so has their mortgage etc.
Still, their houses are very child centred and their lives still are based around the kids. I know a few who tend to act like they are still single and you cannot tell they have kids in the house and kids are shunted off at every opportunity, they drive flash cars and then complain that they can't afford not to work. I agree with the OP that for me I don't see the point in doing that, but we are all different and some people just cannot cope with kids 24/7 or prefer more material things than I would.
I don't get it when people assume you need to be 'lucky' to SAH, I know people who cannot afford to work. Also, I am very non materialistic and choose to live on less money, it is a choice that alot of people could make if they wanted to. Each to his own though.