Whenever somebody says that the team is responsible for product quality most of the time they only refer to the development team. But this is only one side of the coin. What about the rest of the Scrum team? And, in particular, what about the Product Owner?
For sure, the development team is responsible for both internal (maintainability, code quality, code testability, ...) and external quality (stability, usability, performance, ...). Yet I would like to point out how much influence the product owner has on quality as well.