As a practicing programmer who's trying to understand design better, I agree wholeheartedly with this. Just like we're seeing great progress and associated flux in design thinking and tooling (esp. prototyping), front-end programming is also undergoing massive churn, and is an area of specialization that can take you down a rabbit hole that is as deep as you want it to be. There is language churn (Elm, ES6, TypeScript, Flow, Coffee..), framework revolution (React, Ember, Angular, Mercury, Om, ..), flux in CSS methodologies (BEM, SMACSS, SUIT, Atomic), and each of these divisions have many other smaller choices to be made like testing frameworks, utility libraries, promise libraries, async, and so forth.

The point I want to make is that it will take years of practice, attuning to a different way of thinking, and immersing our already limited mental bandwidth to a different field, for either a programmer to become better at design or for a designer to become better at programming. And a lot of this programming churn, for anyone except a professional programmer, is an unproductive use of our lives. We have to keep up in part because of fashion fads, and in part due to the massive entropy inherent in any changing system. But even for a professional programmer, not all of the churn is worthwhile - if there was a way to figure out only those things that matter, those that adds to the essence of our practice, we could simply focus on them, and cut out all the noise. This is unfortunately hard in practice.

However, for a designer trying to be empowered to be also a maker, which the original post talks about, which is also a worthwhile goal, there are good tradeoffs that can be made - things like a basic understanding of the box model, the CSS2 specs and ability to write HTML to understand DOM flow and source order, can make a huge difference in how a designer approaches the web as a medium. Some Javascript will be gravy on top, I'd recommend React's component model, but at the end of the day, how much of our soul do we devote to all these interesting pursuits - would we find inspiration from the colors of nature, keep our eyes peeled to learn design from the real-world, or would we enjoy small pure functions and lovely abstractions? There is a balance to be struck here, which I think is something unique that each of us have to figure out for ourselves.