Sounds like you've never worked in a corporate environment andie. As a junior I regularly worked later than midnight (we all did)... sometimes through until 7.00am. Yes it can suck and if you hate it enough, you leave - so am glad Louise did and is happier now.
Whilst I appreciate she's (Miranda) politically useful I'd be suspicious of her motives
WTF?? I don't regard Mir as "politically useful" but as an intelligent, funny and decent person - I am more suspicious of your motives here, to be honest!