"We do not want the risk. The 3rd party must be accountable for this." Repeat ad infinitum. While it may look like that, dialog happens not because client representatives are dumb. It's because they are afraid. They have toxic corporate culture. It's not safe to fail or discuss possibility of failure. The usual, honestly. So they just want to have a chance to blame someone else and survive when everything goes south.…
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.