I've found the smartest people I know tend to embrace the ethos of this piece almost instinctively. As for those who have to be spoon-fed these strategies? Well, in short: they're not as smart.
The dilemma of defining smart as "can figure out what to do" is that it puts no limitations on intelligence.
Some of these skills are not mastered for multiple reasons: emotional ones like fear and apprehension or lack of familiarity with cultural differences, expectations, etc...
Well - I guess "smart" is just a word that's difficult to define. I think the definition used by the OP is something along the lines of being better at academical subjects, which clearly isn't your only criteria.
I for one used to be quite awkward, but had awesome friends that pointed out what (not) to do. Am I less smart for not having figured that out on my own? Perhaps, but I don't think it's relevant how skills are obtained.
Now, I would argue that you can't necessarily measure this; those you are convinced are the smartest could be significantly less smart, but may be able to trick you into thinking they are the smartest through social skills. In any case, though, I agree to some degree- the smartest can adapt well to most situations, including social ones.
Is this ironic? The article is about not calling people idiots and treating them with respect. Is what you said respectful of people who need to be "spoon-fed" these ideas?
I'd agree. It's quite easy to question the intelligence of someone who tries to socialise, finds it fails again and again, notices that everyone else has no difficulty but assumes the problem is with everyone else.