"I wrote this back in 1989 while I was designing Monkey Island."

The first Monkey Island. Of course the design advice seems fine, since he (and the old LucasArts) applied it in several acclaimed titles that make all the "best computer games ever" lists after the article was written :)

I think the adventure game portion of Lucas Arts was in the process of dying at that point. They didn't release another adventure game after Escape from Monkey Island in 2000. They would have already cancelled a Full Throttle sequel. They had a couple of attempts after this but they were both also cancelled within a couple of years.

Grim Fandango was very good, but honestly the genre got worse after it, not better. Overall the introduction of 3d to the adventure genre had a pretty shaky start. Although there were a couple of exceptions, the genre in general backpedalled for a while.

Ye in retroperspective he was right.

It was at first some years ago with the 'indie' studios publishing on Steam I've played nice adventure games again. 'We Were Here'. Quite good but not very polished.

I think the early 3d mix of 2d backgrounds and 3d characters was allright. Like Grim Fandango or Resident Evil. But ye many of the early pure 3d games didn't work out at all.

Grim Fandango was released in 1998, it is literally 26 years old… also at that time Adventure Games were being eaten by RTS, JRPG, and soon after shooters. It was easy to feel low when looking at the scene.