I find his writing full of technical holes.

It wasn't about technology, it was about public attitudes toward technology as reflected in written Science Fiction.

The hippies won quote blatantly ignores the leaps in science and technology since then.

The "hippies won" quote was Tom's, not McKnight's (and see Tom's follow-up, here). Furthermore (as above), that section of the piece was about societal attitudes, not about either science or its application in technology.

What typical Cold War-era sci fi produced was a linear extrapolation of technological development while assuming culture as a constant. For all its intentional silliness, the epitome of this view was the cartoon series The Jetsons, with its 1950s nuclear family living in a world of flying cars and talking robots.

That was what the world was supposed to be: mid-century middle-class America reproducing itself endlessly, just with better gadgets. The destruction of that vision, the rejection of that future, is what Robinson laments.

It ignores all the space based computer, video and arcade games. For all the slams on Star Trek it has had quite a good long run and everything gets old eventually. Look at the top movies of all time.

Granted, there is a Hugo Award for "Best Dramatic Feature", but Spider Robinson's whine (the kick-off point for McKnight's op-ed) was about the stories and novels, not the special-effects showpieces. Take another look at those movies on your list - not their sales, but their content. Of the twelve, I haven't seen five of them (Phantom Menace, Clones, MIB II, Armageddon, and Signs), but with the exception of Signs I either know or can reliably guess: No Thinking Required.*

The kind of SF that wins Hugo (Nebula, Campbell, Heinlein, Clarke) Awards is definitely not "No Thinking Required" fare. Quite a few individual episodes of the Star Trek series (plural) have won Dramatic Presentation Hugos precisely because they do make one think.

The idea that space no longer holds fascination for the public is preposterous...

What McKnight said was:

What typical Cold War-era sci fi produced was a linear extrapolation of technological development while assuming culture as a constant. For all its intentional silliness, the epitome of this view was the cartoon series The Jetsons, with its 1950s nuclear family living in a world of flying cars and talking robots.

That was what the world was supposed to be: mid-century middle-class America reproducing itself endlessly, just with better gadgets. The destruction of that vision, the rejection of that future, is what Robinson laments.

and

And space projects with no real goal other than the glorification of the state came to a similar end. Thus, von Braun's state-dominated, heavy engineering dominated future never came to pass.

I added the emphasis - in my opinion, space projects with real application, or those of pure scientific exploration, have not suffered the same fate.

... and is falsely promoted by mentioning a series that is not even in the drawing ballpark of a true life space yarn.

Are you talking about his use of "Buffy" as one of three examples of the popularity of fantasy, which he uses in comparison to Robinson's favorite utopic dreams of forty and fifty years ago? Take a look at the so-called "Science Fiction" racks in any of the big-box bookstores, or the list of titles available through the Science Fiction Book Club. What do you see?

By the way... what exactly is a "true life space yarn"? Other than Apollo 13, October Dreams or The Dish, they're all still that particular flavor of fantasy known as Science Fiction.

The hard cash shelled out for other space related movies and polls say differently.

People shell out hard cash for polls? Well, I suppose the space-related PACs and similar organizations do... Otherwise, please see my comments above about written vs visual SF.

I seldom agree with anything he says...

"Careful with that axe, Eugene..."

... and judging from his brief period as executive director of the Mars society feel he has little grasp on how to get anything done in the real world.

That's not the impression I get - in fact, he has some advice I think you ought to take to heart:

Leaders don't whine about how lame their troops are: they train them, educate them, inspire them, and lead.

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[* - Interestingly enough, none of my favorite sci fi flicks are on that list: 1984, 2001, Soylent Green, Gattaca, Contact, Minority Report... Must be because they make me think.]