The resignation of the chief executive of the Care Quality Commission comes not a moment too soon. Indeed, we would argue that Cynthia Bower should rightly have been sacked several times already, given the litany of scandals that has beset the health and social care watchdog during her years at the helm.

Yesterday's Department of Health review of the CQC is surprisingly gentle, even allowing for the muted language of Whitehall. It acknowledges that more could have been done. But, it concludes that, taking into account the difficulties of creating one new regulator from three predecessors, the CQC's achievements are "considerable".

We disagree. Difficult or not, the fact remains that the CQC failed to discharge its fundamental duty to ensure decent patient care. Responsibility for such a failure must lie with the chief executive, particularly when she is as well-remunerated as the £195,000-per-year Ms Bower.

As the former chief executive of the West Midlands health authority – at the time when dire standards at Stafford Hospital contributed to hundreds of deaths – Ms Bower was always a controversial choice for the CQC.

Trouble started almost immediately. Before a year was up, the CQC chairman resigned after a hospital rated "good" was, barely a month later, shown to have the worst death rate in the country. Then came revelations of abuse of patients with learning disabilities at the Winterbourne private hospital and, worse, the admission that the CQC had ignored a former staff member's efforts to alert it.

Ms Bower should have lost her job immediately. But she did not. Neither were the criticisms of the Health Select Committee, growing evidence of shocking treatment of the elderly in any number of British hospitals, or allegations of a "culture of bullying" at the CQC enough.

Ms Bower's supporters say she was hamstrung by an impossibly wide remit, a limited budget and a focus on "light-touch" regulation. Yesterday's report points to improvements in the past nine months. No matter. Only without Ms Bower can the CQC be sure of the root-and-branch overhaul it desperately needs.