She tried to discuss it, for 18 long months, apparently (the op was quite bored by it, and saw it as a massive inconvenience, having to persuade his Dw endlessly to shut up and put up.)
But quite. I don't imagine that she just woke up one morning and thought 'ach, can't be arsed, I wanna be kept'. Imagine how unhappy you'd have to be to make a decision like that, knowing that if you discussed it, your dh would be half arsedly listening whilst ramming home the fact she wasn't allowed to leave, and if you didn't discuss it and just left, he'd be slagging you off on mumsnet.
Pretty win win situation there, obv. I don't imagine it's doing her mh any good knowing that she's no longer contributing to the family finances either. (Although, as he's said it was yonks ago and nothing much has changed, it can't have made that much difference to their 'lifestyle'.)
And with no disposable cash, I doubt she's swanning round the shops and lunching with her mates. She's probably miserable at home knowing her dh thinks she's worth less than something he trod in earlier, and trying to get her self esteem back together after 18 months of misery both at work at home.
Life of Reilly I don't think.