Learning a new language is fairly easy. Learning the language's standard library to the point that you don't have to look at the reference docs every 30 seconds takes a bit more time.
I think the point of the article is that being smart at puzzles is not enough. It may not matter whether you have 3 or 10 years of programming experience, but if you have 20 years of puzzle solving experience with only 6 months of (real-life) programmering experience you have a lot of non-trivial learning left to do.
Being in a startup setting where everyone (usually) is expected to be a bit of jack-of-all-trades, I would argue that having programming experience trumphs being smart, at least for the first period. You may be the master of finding smart algorithms to design your application, but if you can't build the first CRUD website it does you little good.