Is the role of QA to:
Find bugs? (By 'breaking' software)
Prevent bugs?
In a traditional Waterfall Software Management structure, QA is considered an independent, separate validation phase which is performed after development. It's primary role is to provide an independent assessment of 'quality', from specialist I-Shape professionals.
Their feedback however, encourages rework and can constitute to being a bottleneck to Continuous Delivery. Being a Gated Phase near the end of the process, QA departments frequently get blamed for 'holding up' delivery, especially because rework compounds at later stages - fixing bugs late is expensive
The inverse of this is to see QA is a Continuous Process