The trope is that an unpopular decision is made within the organization and then consultants are brought in to execute that unpopular decision and absorb the fallout as if it were the consultants decision.
The reality is that people within a large bureaucratic organization often need a decision to be made that has impacts which extend beyond their narrowly defined responsibilities. Consultants are brought in to make the decision instead, to put space between the employees and the decision. The decision might be unpopular or popular, that’s besides the point.
If you’re an employee with a role doing x, putting your head above the parapet and volunteering to do y, it’s a huge risk, for little reward. Best case, the big corporate you work for gives you a pat on the back and a gift card. Worst case, you’re the sacrificial lamb at the altar of accountability. Much easier to offload everything onto consultants to dodge any risk of being held accountable for a bad outcome.
So, yes, consultants protect employees, but not in the cynical way the trope suggests.