If you haven't yet, I encourage you to read the Inside Higher Ed article about a department that, when a candidate they had made an offer to attempted to negotiate the terms of that offer, then rescinded that offer.
Let me be clear up front: I'm on the side that finds the department's behavior reprehensible and inexcusable. (As is often the case, I should acknowledge that I have only the limited information available.) I admit I view this in the larger picture of the current state of employer-employee relations, where I think the scale has tilted too far in favor of the employer side. Others have noted that there seems to be a prevailing attitude that current employers, by and large, feel employees should be grateful that they're having the opportunity to work for them, regardless of conditions. For a recent example article expressing this, you can read this New York Times article on "My Life as a Retail Worker". While tech workers may think they're in a happy state where employers need them so much that they have to treat them well -- something that, generally speaking, clearly has some truth to it -- I worry on the tech side that has made people complacent. The ongoing story about how Google and Apple (as well as other tech companies) had a secret agreement not to recruit each other's employees demonstrates that, even in tech, the utility of workers and their employers may not always naturally align.
Was the candidate in question asking for too much? I think the candidate was negotiating; she makes clear that she was not expecting to get everything asked for, but wanted to see what was possible. The department chair (or whoever was in charge) should have explained what was possible from their standpoint, and set a deadline for the candidate to decide. To rescind the job offer smacks of discriminatory practices -- not (necessarily) discriminating against women (an issue that has been raised in this context, since maternity leave was part of the request) -- but discriminating against employees that might think to advocate for themselves. Many employers seem to call employees that advocate for themselves "troublemakers"; is that how we're to interpret the mindset behind the decision here? That's disturbing -- as a general trend in academic life and specifically with this university's behavior. I'd like to think people who self-advocate are desirable for tenure-track positions, not the opposite.