I agree Longtalljosie, and wonder how much of this is a genuine sense of not enjoying it and wanting to rush back to work, (which is fine) or just feeling embarrassed by the status of a sahm, as the sahm is currently presented in pop culture: the invisible drudge who watches too much daytime telly, no identity, dependant and should strive to be economically active.
This is an attitude I've seen here, in the media, newspapers, telly etc. since the past 3 governments have slowly made it their combined mission to get all parents out working whilst subtly, insidiously, undermining and pushing out the usefulness and relevance of a sahp.
Fewer people are going to feel confident or comfortable doing a job which isn't respected. I do wonder how much of the " oooh I couldn't do it, I'd be bored, braindead, I need stimulation" mentality comes from a truly real, authentic sense of not being happy (with the obvious exception of pnd) and how much of it comes from knowing that sahparenting is currently frowned upon and in the process of being squeezed out as an option by successive governments. So it's all a bit embarrassing and quick, get the power suit back on and off to the office, don't want to let the sisterhood down..