The reason one should avoid naming another as a "Named Insured" is not to protect you when your own negligence is the cause of a loss- you're on the hook then, anyway.
Remember, though, that the cost of defense is a huge element in any casualty loss situation, and in the event of a loss (accident, occurrence, whatever), everybody remotely involved (and, sometimes, those who are not involved at all) typically gets sued and has to defend themselves.
When this happens, the named insured (who may, for the sake of discussion, be mostly or fully liable for the loss) is, by contract, entitled to be defended by the carrier, and they'll be defended on your carrier's nickel. Add up attorneys' fees, expert witnesses, depositions, etc., and pretty soon your insurance policy has paid out a couple of hundred grand of your million-dollar limit defending the bad actor, and if you are ultimately found liable for some damages, the money spent defending that other guy is not available to indemnify you against the loss.
My policy is, always has been, wherever possible, you should avoid naming others as additional insureds, and if you must do so, do not allow language such as "...primary and non-contributory..."
Finally, beware of unreasonable indemnification provisions, which can "back-door" equivalent treatment for the airport; any agreement to indemnify should be "to the extent of [your] negligence or fault..." or words to that effect. Many you will see will be "broad-form" indemnity, which provides that you are indemnifying them against claims, losses and causes of action, even where they arise out of the negligence of the indemnified party.
Not good.
(This advice is worth every penny you paid me for it)
