These are just rhetorical devices. An active Wikipedia account is just standing in for active participation in sharing knowledge online. S.O. obviously counts, and MDN probably does too (I know nothing about it).

Arduino is standing in for, knowledge of things that aren't directly applicable day-to-day. Hobbyist stuff.

I think it's acceptable to define a good programmer in terms of qualities that aren't beneficial to business. In the real world this is one reason why we have and need management. A big part of management's job is to convey to the rest of staff what the business goals are and how they are to be achieved. It would be nice if all programmers synthesized this without having to be told, but I don't see why that should be considered a necessary prerequisite for being a good programmer.

ThinkGeek toys, obscure stuff are just specific examples of a general pattern of curiosity and playfulness.

This is Metonymy:

"Today The White House issued a statement..."

This is not:

"Has an active Wikipedia account"

Metonymy is the use of a name (usually something specific like a building, or a part) to stand for something else (usually more general, like a government or organisation, or the whole thing), not the use of one example website with lots of others implied (I don't see where they are implied anyway, this is quite explicitly listing having a wikipedia account as an attribute of a good programmer - what a curious idea).

Most of the symptoms are just trivia entirely unrelated to whether someone might be talented at programming like owning a certain brand of toys, and this undermines anything serious the writer might want to say.

I misremembered, but I can't seem to recall the name of the device where you show a specific example from a class to stand in for the whole class. This is remarkably hard to search for. Please be useful and remind me what the proper name of the device is.

I think everybody is taking this article both too seriously and too literally. Sadly there is no known cure.

I believe that's synecdoche.

Thank you.

Signs that you have a general pattern of curiosity and playfulness could also likely include a molecular biologist with a picture of Lil Jon on her wall.

Following a general pattern is still a pattern. Patterns aren't as interesting as anti-patterns.

The Arduino is pretty well known, it's a tell if you somehow have not heard of it - it shows you haven't spent much time looking at side projects.

Or you're more interested in side projects that don't have a hardware or physical component. Or that require much more specialized equipment, like a CAVE system. Or don't use electronics at all, like 3D printing representations of mathematical functions, or building a cabin in the woods. Or restoring linotype machines.

Side projects in this case refers to programming side projects, I'm fairly sure. Personally I'm not interested in side projects with hardware or physical components, but I've still heard of the Arduino. But that really says more about the type of people you know, I guess.

True, but there are plenty of programming side projects that don't require an Arduino, and we often get in our little tech-bubbles and think that the internet is more of a monoculture than it actually is. I've heard (a lot) about the Arduino, so I may not be the best example, but my programming side projects are more likely to use Processing, Cinder, VPT, or some other thing that doesn't necessarily need to interface with that kind of hardware.

If we're talking about the original article, side projects were mentioned in the context of "The instinct to experiment first". There might be some correlation there, but if you limit the focus to programming side projects you've just chosen a slightly bigger box to experiment in.

Many advances in science come by drawing knowledge from a completely different field and applying it to a familiar one. Deep knowledge of programming is necessary but not sufficient for creative programming solutions. Design patterns in software, to take one familiar example, are based on Christopher Alexander's theories about physical architecture. The article itself recommends amusement park rides to foster greater risk-taking. Non-programming hobbies can have great benefits for programmers.

I've never met a good programmer who wasn't passionate about side projects. In fact every bad programmer I've met had no interest in side projects, summer projects, etc.