I read the article and though of MN too.
At first I agreed with her to an extent - I do know some mums like that (ie nail bars and lunching), but most of the FT SAHMs I know just spend a lot more time with their kids playing - not sure whether that's good or bad, but that's how it differs from the 'olden days'.
I think it was easier back then to leave kids to play on their own - as a child growing up in the 60s and 70s I could just disappear on my bike after school and come back at dusk, build dens in the local copse, go for long walks over the fields etc, without my mum tearing her hair out and dialling 999. Could any of us do that today? I doubt it. I think you'd have had a lot more mums on Prozac (or Valium in those days) if they hadn't been able to just let their kids entertain themselves.
Aloha is right though - the difficulties of WOTH when your kids are at school make it almost not worth the while. I normally work from home but am doing a 6 month in-office contract for 3 days a week, 9-5 soon. The school & nursery drop-off/pick-up routine would be impossible if DH wasn't also working from home and could do it instead of me. I've tried to get DS1 in afterschool club but there are no places! It's much easier when they are pre-school and you can choose a day nursery which offers care till 6pm or whatever.
I'm lucky being able to work from home. TBH if I didn't, and my DH couldn't be flexible with his job, then I really don't know what I would do.
So, yes, I would agree with Carol Sarler - I think many mums would like to WOTH once their kids are at school - but until we see more 9.30-3pm jobs (and I mean career type jobs other than teaching) or greater provision of accessible before-and after-school care, most mums will see it as more trouble than it's worth.