Sure it is. Asking a question has several dimensions along which to afford skill. General social skills aside, question-asking specifically has the extra challenge of "get someone to give me the information I need", and some people are demonstrably much more effective at this than others.
I've certainly witnessed people who really needed to know something and were completely unable to express what they needed. If you're talking to a skilled question-intuiter then this is less of a problem, but if you're not, then you need to be correspondingly better at asking your question so as to get an answer that is useful to you.
I agree that a statement in this generality is non-sense. (If it were a skill, how would you acquire it without asking a question.) What is meant here (probably) is sth. like "asking a good question" is a skill -- where "good" could be defined in any number of ways. In this context, it's probably synonymous to "getting the reply you're actually after without someone closing your question, or marking it as a dupe". That probably is a skill.
However, SO would be a more useful place, especially but not only for newcomers, if that skill wasn't required. If anyone could ask anything, and as long as there's someone willing to answer, it doesn't matter whether the question could be deemed "skillful" by any measure.
There are a number of reasons why SO isn't that place, and I can see why these reasons exist. It's a fun thought experiment to think about whether SO would have made it to the place it is today if it had started out already with the same draconic rules and views on how questions should be written as are in place today.
Let's consider the question you have just asked here. As the article you are responding to has presented several arguments for the proposition that it is a skill, a good follow-up question would challenge one or more of the claims or inferences made in that article, or raise a point that seems to have been overlooked. A question that ignores everything that has already been said on the issue is not likely to elicit anything new.
