That is interesting. Can you imagine how much wordier it would make me if I wasn't allowed to use "thought" verbs, though?! Good lord! Judging by the examples in the article, every scene would end up being like three times as long!
In theory, it's a good idea. Show, don't tell is a basic rule for good fiction writing. That said, I think there's a time and a place for descriptive sentences full of sensory details that reveal something about the setting or characters... and then there are times when it's better to just tell and move on because it's not that important. I have to admit, I got bored just reading some of those examples, but like Mare said, I don't think they were the best-worded examples of what the writer was trying to illustrate. Too many commas! (And I say that as a lover of correctly-used commas.)
I have read stories by authors who take "show, not tell" to the extreme, much like the author of this article, and describe every little thing in great detail, to the point where I can't even tell you what those stories were actually about. I think the way to "show, not tell" correctly is to pick the IMPORTANT things to show and describe and save the telling for minor details that don't really matter that much. If you're revealing an important character trait, by all means, show it! Don't just tell us what your character is like or how they feel about another character. But I think it's okay to say something like, "Brian hated bologna," in a scene in which Brian is offered a bologna sandwich because, most likely, the point of the scene isn't to show how much Brian hates bologna - it's just one of those little quirks you add to help bring his character to life. If you went off on a whole tangent in which Brian gags as he looks at the bologna, imagining what kind of leftover animal innards were ground together to make it, you would lose the whole point of the scene.
(While writing this, I just realized I hate how the word "bologna" is spelled as much as I hate bologna itself. Bologna fails twice! And now I, as my eyes roam across the first sentence in this parenthetical aside, I see that I used two "thought" verbs - realized and hate - so now I am attempting to show, not tell my feelings about bologna. Oh crap, I just told you what I was doing again. I wrinkle my nose and heave a heavy sigh, scratching my head as my fingers hesitate on the keyboard... then I keep typing to stall for time while I try to show what is going through my head without using thought verbs. Do you see what it would be like if I wrote this way all the time? I shake my head, wide-eyed, as I imagine scrolling past scene after scene of this overly-descriptive drivel. Uh oh, I think "imagine" is a thought word. Oh shit, so is "think." I give up.)
Anyway, I think you should show most of the time and tell in moderation. That's my take on it.