> Not exactly, because someone who explores other technologies unrelated to his/her "work" field will inevitably pick up experience and knowledge - which the employer can grab for free without sending the employee to expensive courses or having to hire highly specialized freelancers.

I don't think there is any debate that, in general, someone who tinkers, explores, and codes outside of work will be relatively better than someone who doesn't. That is not the same as saying the former is above some absolute line while the latter is below it. This is the characterization that people here, including me, take issue with. You can easily be competent and effective while not spending time outside of work writing code.

>I don't think there is any debate that, in general, someone who tinkers, explores, and codes outside of work will be relatively better than someone who doesn't.

I've found that the truth of this depends almost entirely on the type of coding one is doing at work.

If you're doing challenging work all day and then do some challenging work after hours, you'll likely be better than most based on the sheer amount of practice.

If your day job is mostly a joke and you are maintaining systems that you don't really understand, coding all night won't make you better than someone who is doing challenging work all day and logging off entirely at closing time.

Hence why I said "in general", though after considering what you wrote here there may be more exceptions than I thought.

You're not wrong. But some people don't like to stare at a computer and program for 8 hours a day and then go home and keep doing it. They may have other responsibilities or other hobbies, or just a highly active social life.

There was a time when I was younger where I spent a lot of time outside of work programming, but I also didn't have any other hobbies (well, playing video games doesn't really count), no responsibilities, and almost no social life. Now that I'm older and have all three, programming at home is a luxury I often choose not to do. But that doesn't make me a bad programmer.

One could just as easily argue that you're not a "bad programmer" specifically because you used to spend so much of your free time programming.

But the point is that it totally depends on the person and it's not this hard and fast rule.

It's also vague to the point of meaninglessness considering all the various kinds of technologies and depths within those technologies one might be toying with in their spare time.

I would argue that the general intuition that many programmers have about people who code in their spare time is simply a too-narrow view of the picture. It's more about people who are really good at LEARNING, and people who code in their spare time tend to become very good at self-teaching new things and figuring out how different systems work and interact.

A developer can be good at learning as long as he or she is practicing learning something in their spare time, but I don't think it has to be a side project (or even technology-related at all) to see a benefit in professional productivity.

> A developer can be good at learning as long as he or she is practicing learning something in their spare time, but I don't think it has to be a side project (or even technology-related at all) to see a benefit in professional productivity.

This is an excellent point. I have lots of side projects outside of work. At the moment, none of them involve code but they all involve learning things; some of them are even fairly technical.

People used to have "hobbies". Now it needs to be a side project.