There are pros and cons of having dedicated teams for work that also has to be accomplished by other teams. For instance, it's not a good idea to skip having a security team using the logic that "other teams will just think its that one teams job." The security team provides expertise and (with cooperative management or other teams) can enact policies that influence the rest of the organization to the benefit of security. That can't happen without a set of people dedicated to thinking about those problems.

For your QA team example, the mistake made in some organizations is explicitly removing testing from developer's responsibilities.

It's a matter of BOTH/AND -- you need to have BOTH central teams responsible for long term health of {safety,privacy,security,testing,etc.} AND hold developers responsible to deliver the recommendations of and use the tools developed by central teams.