I woke up to see my other comment downvoted by some rando, but I honestly think this is the best line in the entire article and Gruber's wish is telling (I quote the line only here, but it is best read in context of the original passage):

"I wish Apple would make a MacBook that’s akin to the iPhone Air — crazy thin and surprisingly performant."

What this reflects is all those comments and users, myself included, over the years saying "I would get an iPad if only it could run MacOS", and the ensuing discussion to the effect of why Apple won't do it, the chips are just as powerful, etc. A tablet Mac is a lot of people's (both casual and tech) holy grail in portable computing, justified/sensible or not in terms of technology and UI form factor. Gruber's wish is precisely the expression of this not unpopular sentiment. And also the Tahoe iPad OS features is a clue that Apple knows this.