So the public sector should not hire private contractors in general. State it like that then.

How is a mismanagement of consultants by public sector entities a justification to “ban” an entire sector?

Well the least they can do is force band auditing companies from offering consulting services because that is a clear conflict of interest..

That I do agree with.

BCG and McK don’t offer auditing.

We should probably ban the "no skin in the game part" instead of just the sector. Even though there have been a few court cases, the effect was tiny and they are still considered reputable. In some cases probably more personal lawsuits should be done more often (also for politicians and civil servants)

I don't get it. Do you think auditors and consultants that screw up on their job should be prosecuted?

Depends on the nature of the screw up and on how high up the hierarchy they are.

At a sufficient level of negligence and authority -- yes.

I was objecting to "you don't pay them" specifically.

With governments having like 30-50% GDP share of the economy (e.g., tax versus GDP) - we are gonna have a hard time banning literally everything based on that…

That was Booz Allen Hamilton, they are a government subcontractor that largely provides long-term staff augmentation... totally different type of professional services than strategy consultants or even system integrator (SI) shops like Accenture and Deloitte.