[ZWoz]

Good managers are like firewalls: they shield from negative outside influences and let good or important information and tasks pass.

That includes representing department in stupid meetings, instead of wasting developers/engineers time.

[andsoitis]

Insulating developers from the rest of the business or other engineering teams is a hallmark of a poor manager, not a great one.

[Intermernet]

Kelly Johnson would disagree, and his management style is taught around the world.