Colour me another one completely mystified by the Keiko-hate. Even more so when she's painted as worse than Kai-m-f-in'
Winn (who ordered an
assassination attempt against Bareil Antos). Yeah, Keiko was more than a trifle sanctimonious in 'ItHotP', but, to her credit, she never tried to put out a hit on anybody... And regarding mean commentary about cooking, are the Keiko-haters conveniently forgetting that 'I'm not a fish' O'Brien comment during 'The Wounded' for some reason?
Speaking of her relationship with the Chief, I get the feeling she was probably a
tsundere, and that has a certain appeal to some men (including myself, in the interests of full disclosure). And yeah, it was clear she hated the Bajor posting. But when push
really came to shove, she proved herself incredibly loyal and supportive to O'Brien: 'Armageddon Game', as mentioned before, but also 'Tribunal' and 'Time's Orphan'.
Neither of the characters is perfect. But that was the point of DS9, to a pretty significant extent.
EDIT: And no one - I repeat,
no one - can
possibly out-bitch Vice Admiral Nechaev (though, I admit, the Female Changeling and Kai Winn do give her a run for her money). The way she treats Picard
and Sisko is borderline unprofessional, and her 'you
will commit genocide on my order' attitude is just
begging for a good fragging... for the greater good of the Federation, natch.