Mxsmanic writes:

I'm just wondering if those pilots who landed on a taxiway had their licenses
revoked, too, since they also deserved to be grounded.

Not sure that merely landing on a taxiway is cause for license
revocation. That would be a single momentary mistake; the NW pilots made
a series of careless mistakes over an hour or more.

BTW, what about landing at the wrong airport? Some airliner did that
many years ago, confusing then-Moffet Naval Airstation in the south Bay
Area for the intended San Jose Municipal (back then it was Muni, not
Intl.) Don't know what happened to them.

I saw a bizjet land at the wrong airport a few years ago. A 3-engined
FalconJet landed at my home airport (KEDU) by mistake instead of its
intended KDWA (No. Calif). Runways: KEDU 3176 x 50 ft; KDWA 6000 x 100
ft. This was mid-morning, full sunshine. It was kinda funny for us on
the ground, we all heard the roar of the approaching jet, couldn't
believe it was going to land, and as soon as the mains touched the PIC
kicked in reverse thrust, full power. Somehow he made the turn onto the
end taxiway and parked, found out he was at the wrong place. Even
stranger to watch him take off, we don't get many jets here . We joked
he wasn't going to log that airport.