If you choose a 3rd party partner in the company I work for and that partner fails: it reflects badly on you, do it more than once and it can be pretty detrimental to your future inside the company.
You are responsible for the third parties you vouch for.
FWIW this is not ideology, this actually happened.
IBM survives in large part because they are a third party you can hire without really putting your own neck out there as the biz folks trust them.
At a prior job it was CGI. CGI got a ton of work as when they failed, the lower level people didn't get blamed. Any other vendor would have led to the negative reflection you mentioned.
PwC was seen by him to be the safe choice because they were so large and essentially industry standard. He got flak because he didn't do appropriate due diligence. That was his job, so...